Alterations of the human gut microbiome in liver cirrhosis.

Liver cirrhosis occurs as a consequence of many chronic liver diseases that are prevalent worldwide. Here we characterize the gut microbiome in liver cirrhosis by comparing 98 patients and 83 healthy control individuals. We build a reference gene set for the cohort containing 2.69 million genes, 36.1% of which are novel. Quantitative metagenomics reveals 75,245 genes that differ in abundance between the patients and healthy individuals (false discovery rate < 0.0001) and can be grouped into 66 clusters representing cognate bacterial species; 28 are enriched in patients and 38 in control individuals. Most (54%) of the patient-enriched, taxonomically assigned species are of buccal origin, suggesting an invasion of the gut from the mouth in liver cirrhosis. Biomarkers specific to liver cirrhosis at gene and function levels are revealed by a comparison with those for type 2 diabetes and inflammatory bowel disease. On the basis of only 15 biomarkers, a highly accurate patient discrimination index is created and validated on an independent cohort. Thus microbiota-targeted biomarkers may be a powerful tool for diagnosis of different diseases.

[Characteristic of urinary protein spectrum in patients with stage III diabetic nephropathy and its regression analysis with traditional Chinese medicine symptom].

To analyze the characteristic of urinary protein spectrum in patients with stage III diabetic nephropathy (DN) and its compliance with traditional Chinese medicine (TCM)symptom, for the sake of providing a basis for clarifying the rules of TCM syndrome differentiation in DN. Adopting the traditional epidemiological retrospective method, thirty-eight TCM syndromes and urinary protein with medium or low molecular weight, as well as urinary enzyme, including 24 h urinary protein (Upro), urinary albumin( UAlb), urinary retinal binding protein( URBP), urinary cystatin C (UCysC), urinary N-acetyl-beta-D-glucosaminidase (UNAG), were collected from 108 patients with stage III DN, and a multiple factor regression analysis between them was conducted. As the results, the levels of Upro, UAlb, URBP, UCysC, and UNAG were increased in 108 patients with stage III DN. Qi-Yin deficiency type was the major type. The level of UAlb in patients with Qi-Yin deficiency type was significantly higher than those without Qi-Yin deficiency type (P < 0.05). The elevation of Upro with the factors as swift digestion with rapid hungering, lassitude and lack of strength, weakness of waist and knees was complied, the elevation of UA1b with the factors as dry mouth with desire to drink, the elevation of URBP with the factors as numbness of extremities, shortness of breath, the elevation of UCysC with the factors as clear urine in large amounts, and the elevation of UNAG with the factors as frequent micturition, were complied respectively. In conclusion, for 108 stage III DN patients. The increase in urinary protein spectrum including UAlb, URBP, UCysC, and UNAG is the major characteristic. Shen and Pi are the major organs related to the appearance of urinary protein; Pi-Shen deficiency is the basic pathogenesis. The level of UAlb is taken as one of the objective syndrome factors for Qi-Yin deficiency type. The levels of UNAG and UCysC are possibly the objective syndrome factors for Shen-Qi deficiency type.

High spatial frequency periodic structures induced on metal surface by femtosecond laser pulses.

The high spatial frequency periodic structures induced on metal surface by femtosecond laser pulses was investigated experimentally and numerically. It is suggested that the redistribution of the electric field on metal surface caused by the initially formed low spatial frequency periodic structures plays a crucial role in the creation of high spatial frequency periodic structures. The field intensity which is initially localized in the grooves becomes concentrated on the ridges in between the grooves when the depth of the grooves exceeds a critical value, leading to the ablation of the ridges in between the grooves and the formation of high spatial frequency periodic structures. The proposed formation process is supported by both the numerical simulations based on the finite-difference time-domain technique and the experimental results obtained on some metals such as stainless steel and nickel.

The single Z-plasty for cleft palate repair: a preliminary report.

OBJECTIVE: To introduce a surgical technique for the repair of cleft palate with the single and full-thickness Z-plasty method. PATIENTS AND METHODS: The procedure was performed from 1999 to 2006 in 34 patients with cleft palate with a median age of 6.0 years (range, 2.0 to 21 years). In these patients, in order to push the soft palate back farther, a single and full-thickness Z-plasty, designed on the soft palate across the defect, was applied to the von Langenbeck procedure. The full thickness of the soft palate was incised after the hard palate was closed by suturing the two mucoperiosteal flaps, and two Z-plasty flaps were formed. The two flaps were then transposed and closed by interrupted suturing of three layers of the palate in proper order, from nasal mucosa, levator muscle to oral mucosa. The patients were followed for 6 months to 3 years, velopharyngeal closure was examined by nasopharyngeal fiberscope and/or x-ray radiography, and a clinical speech evaluation was performed. RESULTS: In all patients, no problem of flap viability was encountered and all healed well. The postoperative results were satisfactory without any complications such as dehiscence, perforation, or palatal fistula. The clinical speech evaluation was satisfactory, and the effects of the operation were stable. CONCLUSIONS: The technique presented has been effective, having the advantages of palatal closure without tension and with sufficient lengthening of the soft palate.

The delayed repair of sciatic nerve defects with tissue-engineered nerve grafts in rats.

The purpose of this study was to evaluate the feasibility of using tissue-engineered nerve grafts for delayed repair of peripheral nerve defects. A 1-month delayed, 10-mm long sciatic nerve defect was created for rats, which were divided into three grafted groups and a non-grafted group. For bridging the nerve defects, the rats in three grafted groups were subjected to surgical repair with tissue-engineered nerve grafts made of a chitosan/polyglycolic acid (PGA) conduit filled with neural stem cells (NSCs), chitosan/PGA conduits, and autologous nerve grafts, respectively. At 3 months after nerve grafting, the data from electrophysiology, retrograde tracing and histological investigation revealed that the better outcomes in sciatic nerve regeneration and target muscle re-innervation were achieved in three grafted groups as compared to those in non-grafted group without major differences between three grafted groups. Our results suggest that grafting of chitosan/PGA conduits might be a promising technique for repairing peripheral nerve injuries after a 1-month delay, while introduction of NSCs seem to show no significant additional benefits to regenerative outcomes.

Comparison of Achilles tendon repair techniques in a sheep model using a cross-linked acellular porcine dermal patch and platelet-rich plasma fibrin matrix for augmentation.

The primary goal of this study was to evaluate a cross-linked acellular porcine dermal patch (APD), as well as platelet-rich plasma fibrin matrix (PRPFM), for repair of acute Achilles tendon rupture in a sheep model. The 2 surgically transected tendon ends were reapproximated in groups 1 and 2, whereas a gap was left between the tendon ends in group 3. APD was used to reinforce the repair in group 2, and autologous PRPFM was used to fill the gap, which was also reinforced with APD, in group 3. All sheep were humanely euthanized at 24 weeks after the repair, and biomechanical and histological testing were performed. Tensile strength testing showed a statistically significant difference in elongation between the operated limb and the unoperated contralateral limb in groups 1 and 3, but not in group 2. All operated tendons appeared healed with no apparent fibrosis under light and polarized microscopy. In group 1, all surgical separation sites were identifiable, and healing occurred via increasing tendon thickness. In group 2, healing occurred with new tendon fibers across the separation, without increasing tendon thickness in 2 out of 6 animals. Group 3 showed complete bridging of the gap, with no change in tendon thickness in 2 out of 6 animals. In groups 2 and 3, peripheral integration of the APD to tendon fibers was observed. These findings support the use of APD, alone or with PRPFM, to augment Achilles tendon repair in a sheep model.

The effect of entrapped bone particles on the surface morphology and wear of polyethylene.

Clinically retrieved highly cross-linked ultrahigh molecular weight polyethylene (HXPE) acetabular liners have demonstrated scratching, whereas conventional ultrahigh-molecular-weight polyethylene (UHMWPE) implants show a smoother surface early after implantation. In the present study, the potential of bone particles and soft tissues, rather than cement, to scratch the articular surface of HXPE and UHMWPE (gamma radiated) acetabular components was evaluated; multiple bone particles located at the articular surface for 3600 simulated walking cycles replicated the scratches observed on retrieved implants. By remelting, these scratches were confirmed to be due to plastic deformation of the polyethylene, not wear. Furthermore, it was shown using wear testing that these scratches did not affect the subsequent wear rate of HXPE or conventional UHMWPE. Wear rates of scratched conventional and cross-linked polyethylene were not significantly different from unscratched conventional and cross-linked polyethylene, respectively.

Fixation of tissue-engineered human neocartilage constructs with human fibrin in a caprine model.

The primary objective of this study was to determine the retention rate of neocartilage constructs in caprine full-thickness cartilage defects by fibrin sealant alone. Two defects, one each on the trochlea and the medial femoral condyle, were created in the stifle joint in 12 goats. Eight goats (16 defects) were treated with neocartilage constructs and 4 goats (8 defects) with fibrin glue alone. Postoperative activity was protected weight bearing for 6 weeks and then unrestricted for 18 weeks. At 24-week procurement, 4 neocartilage constructs were retained in 8 medial femoral defects and 4 in 8 trochlear defects. In gross comparison, the defects that retained the construct had a mean grade significantly higher than defects treated with fibrin glue alone. The mean histological score of defects with retained constructs was also higher than those treated with fibrin sealant alone. There was no appreciable immunologic reaction to the human neocartilage xenograft or human fibrin sealant.

Characterization of a highly cross-linked ultrahigh molecular-weight polyethylene in clinical use in total hip arthroplasty.

This article reports on a commercially available extensively cross-linked ultrahigh molecular-weight polyethylene (HXPE) produced by subjecting molded GUR 1050 ultrahigh molecular-weight polyethylene (UHMWPE) to 100 +/- 10 kGy of electron beam radiation followed by melt annealing and sterilization by gas plasma. When compared to contemporary conventional molded GUR 1050 UHMWPE sterilized by 37 kGy of gamma radiation, the HXPE material has enhanced wear properties, has no detectable free radicals, and is resistant to oxidation and oxidative-related material property changes. The relative wear improvement of the HXPE is maintained in the presence of bone cement or alumina particles. The HXPE produced greater than 90% fewer wear particles in all size ranges and statistically significantly (P < .0001) smaller average-size particles than did the conventional UHMWPE.

Evaluation of a cross-linked acellular porcine dermal patch for rotator cuff repair augmentation in an ovine model.

In this study we evaluated 2 commercially available rotator cuff repair augmentation patches in an in vivo sheep model using mechanical testing and histologic techniques. Bilateral infraspinatus tears were created and repaired in 2 groups of 8 adult ewes. Each group (killed at 9 or 24 weeks) included 5 repaired with suture alone, 6 repaired and augmented with a cross-linked acellular porcine dermal (PD) patch (Zimmer Collagen Repair Patch), and 5 repaired and augmented with a porcine small intestine submucosa (SIS) patch (Restore Orthobiologic Soft Tissue Implant; DePuy Orthopaedics). At 3 weeks, sheep with suture repair and an SIS patch had significant elevation of plasma fibrinogen levels (P < .05) whereas sheep with suture repair and a PD patch elicited no elevation in plasma fibrinogen levels. At 9 weeks, the mean failure load was 201 +/- 60 lb for suture repairs, 182 +/- 63 lb for PD repairs, and 137 +/- 16 lb for SIS repairs. Within any individual sheep, the shoulder undergoing PD repair always had a higher failure load than the contralateral suture or shoulder undergoing SIS repair. At 9 weeks, macrophages were seen on all PD surfaces whereas most of the SIS materials were resorbed. At 24 weeks, failure loads were identical between groups. Macrophages had disappeared from the PD groups, and integration of the PD patch into the surrounding tissue with vascular and fibroblastic invasion was seen. For the SIS group, diverse tissue types (including ectopic bone) were seen.

[Surface-enhanced Raman spectroscopic studies on the thiophenol adsorbed on novel Ag-Au alloy nanoparticles].

Ag-Au alloy seeds were prepared by the simultaneous reduction of Ag and Au salts. The seeds were grown via NH2OH x HCl-growth method to obtain novel Ag-Au alloy nanoparticles with diameters of 40-60 nm. The nanoseeds and novel nanoparticles were characterized by UV-Vis spectroscopy and TEM respectively. The observation of one surface plasma resonance absorption band, the redshift in their frequencies, and the uniform color of the nanoparticles shown in TEM images indicated the formation of alloy structure for both the nanoseeds and the novel nanoparticles. By using thiophenol (TP) as probe molecules, SERS studies were performed on the novel nanoparticles. The absorption bands of the nanoparticles red shifted with the addition of TP, and new bands were detected in the near infrared region, which were attributed to the aggregation of TP covered nanoparticles. With the excitation line of 632. 8 nm, the SERS intensity of TP on Au was most largely enhanced, and that on alloy nanoparticles were increased as X(Au) increased.

Dog sciatic nerve regeneration across a 30-mm defect bridged by a chitosan/PGA artificial nerve graft.

We have developed a dual-component artificial nerve graft comprising an outer microporous conduit of chitosan and internal oriented filaments of polyglycolic acid (PGA). The novel graft was used for bridging sciatic nerve across a 30-mm defect in six Beagle dogs, which were used as a chitosan/PGA graft group. The other Beagle dogs were divided into an autograft group (n = 6) as the positive control and a non-grafted group (n = 5) as the negative control. All animals of three groups were monitored for changes in their appearance and locomotion activities after surgery. Their posture and gait were recorded regularly with the aid of photographs and videotapes for each dog. Six months post-operatively, a combination of electrophysiological examination, FluoroGold retrograde tracing, histological assessment including light microscopy and transmission electron microscopy, immunohistochemistry as well as morphometric analyses to both regenerated nerves and target muscles was utilized to investigate the nerve repair effects of our artificial nerve graft. The results demonstrated that, in the chitosan/PGA graft group, the dog sciatic nerve trunk had been reconstructed with restoration of nerve continuity and functional recovery, and its target skeletal muscle had been re-innervated, improving locomotion activities of the operated limb. This study proves the feasibility of the chitosan/PGA artificial nerve graft for peripheral nerve regeneration by bridging a longer defect in a large animal model.

Evaluation of biocompatibility of polypyrrole in vitro and in vivo.

In this study, the biocompatibility of the electrically conductive polymer polypyrrole (PPy) with nerve tissue was evaluated in vitro and in vivo. The extraction solution of PPy powder, which was synthesized chemically, was tested for acute toxicity, subacute toxicity, pyretogen, quantitative measure of cell viability, hemolysis, allergen, and micronuclei. The PPy membrane was synthesized electrochemically on the indium tin oxide conductive borosilicate glass. The dorsal root ganglia from 1-3-day-old Sprague-Dawley rats were cultured above PPy membrane and observed by light or scanning electron microscopy. The PPy-silicone tube (PPy membrane on the inner surface of the silicone tube) also synthesized electrochemically was used to bridge across 10-mm sciatic nerve gap in rats. Twenty-four weeks after the operation to rats, the regenerated tissues were observed by electrophysiological and histological techniques. PPy extraction solution showed no evidence of acute and subacute toxicity, pyretogen, hemolysis, allergen, and mutagenesis, and the Schwann cells from the PPy extraction solution group showed better survival rate and proliferation rate as compared with the saline solution control group. The migration of the Schwann cells and the neurite extension from dorsal root ganglia on the surface of PPy membrane-coated glass was better than those of bare glass. There was only lightly inflammation during 6 months of the postoperation, when the PPy-silicone tube bridged across the gap of the transected sciatic nerve. The regeneration of nerve tissue in the PPy-silicone tube was slightly better than that in the plain silicone tube by means of electrophysiological and histological examination. The results of this study indicate that PPy has a good biocompatibility with rat peripheral nerve tissue and that PPy might be a candidate material for bridging the peripheral nerve gap.

Efficient intramolecular energy transfer between two fluorophores in a bis-branched [3]rotaxane.

A bis-branched [3]rotaxane, with two [2]rotaxane arms separated by an oligo(para-phenylenevinylene) (OPV) fluorophore, was designed and investigated. Each [2]rotaxane arm employed a difluoroboradiaza-s-indacene (BODIPY) dye-functionalized dibenzo[24]crown-8 macrocycle interlocked onto a dibenzylammonium in the rod part. The chemical structure of the [3]rotaxane was confirmed and characterized by (1)H and (13)C NMR spectroscopy and high-resolution ESI mass spectrometry. The photophysical properties of [3]rotaxane and its reference systems were investigated through UV/Vis absorption, fluorescence, and time-resolved fluorescence spectroscopy. An efficient energy-transfer process in [3]rotaxane occurred from the OPV donor to the BODIPY acceptor because of the large overlap between the absorption spectrum of the BODIPY moiety and the emission spectrum of the OPV fluorophore; this shows the important potential of this system for designing functional molecular systems.

Surface enhanced Raman spectroscopic studies on magnetic Fe3O4@AuAg alloy core-shell nanoparticles.

A facile approach has been developed to fabricate multifunctional Fe3O4@AuAg alloy core-shell nanoparticles, owning the magnetism of the core and the surface enhanced Raman spectroscopy (SERS) activities of the alloy shell. By changing the amount of HAuCl4 and AgNO3, Fe3O4@AuAg alloy nanoparticles with different component ratios of Au and Ag were successfully prepared. The surface plasmon resonance of the composition was linearly tuned in a wide range by varying the molar fraction of Ag and Au, suggesting the formation of AuAg alloy shell. SERS and magnetic enrichment effects were investigated by using thiophenol (TP) as the probe molecule. The SERS intensity was strongly dependent on the molar ratios of Au and Ag and the excitation line. Enrichment for the molecules with low concentration and on line SERS monitoring experiments were performed through combining the magnetism of the core and the SERS effect of the alloy shell. The results revealed that the magnetic enrichment efficiency was dramatically increased due to the strong magnetism of Fe3O4 core. In addition, the Fe3O4@AuAg nanoparticles were also used in the microfluidic chip to continuously detect different flowing solution in the channel. The detection time and amount of analyte were successfully decreased.

Development of chondroitin sulfate encapsulated PLGA microsphere delivery systems with controllable multiple burst releases for treating osteoarthritis.

The purpose of the study was to design and develop unique drug delivery systems with controllable multiple burst releases of drugs for treating osteoarthritis. Chondroitin sulfate (CS) was encapsulated into four types of PLGA materials, that is, PLGA 50:50, PLGA 65:35, PLGA 75:25, and PLGA 85:15. The effects of microsphere size and various combinations of blend PLGA microspheres on CS release were investigated. The cytotoxicity of the CS-encapsulated microspheres was investigated according to the ISO 10993 guideline. Our study showed that the encapsulation efficiency of CS into PLGA 50:50 microspheres varied with the size of microspheres; however, the encapsulation efficiencies of CS into PLGA microspheres were independent of the types of PLGA materials. The size of PLGA microspheres was shown to affect the rate of CS release. With the increase of microsphere size from 75-150 µm to 300-355 µm, the initial CS release decreased. Further increase in microsphere size led to an increase in the initial CS release. In addition, combination of different types of PLGA microspheres was shown to be capable of achieving multiple burst CS releases. Moreover, the CS encapsulated PLGA microspheres were shown to be non-cytotoxic. This study proved the concept of multiple burst drug releases that were achieved by encapsulating CS into different types of PLGA microspheres and delivering CS from systems consisting of mixed types of PLGA microspheres, which may be applied to treat osteoarthritis by mimicking multiple intra-joint injection of therapeutic agents.

Wear, delamination, and fatigue resistance of melt-annealed highly crosslinked UHMWPE cruciate-retaining knee inserts under activities of daily living.

The wear, delamination, and fatigue resistance of artificially aged gamma irradiation-sterilized conventional polyethylene (CPE) and gas-plasma-sterilized melt-annealed highly crosslinked polyethylene tibial inserts (HXPE) were compared. Six CPE and 12 HXPE (six irradiated at 58 kGy and six at 72 kGy) left knee inserts were wear tested for 5.5 million cycles (Mc) under loads and motions that mimic activities of daily living, such as walking, chair rise, stair ascent, and deep squatting. Another six HXPE (72 kGy) and six CPE inserts were also tested under conditions that could produce severe delamination for 8 Mc. Ten other knees (five 72 kGy HXPE and five CPE) were subjected to posterior edge loading fatigue testing for 5 Mc. The HXPE inserts had an average wear rate reduction of about 80% relative to their CPE counterparts during all activities. All of the CPE inserts delaminated and fractured during high cycle deep squat (152 degrees flexion) motions, while all the HXPE remained intact. None of the HXPE inserts delaminated after 8 Mc, while all of the CPE inserts developed delamination damage within 1.5-5.8 Mc of delamination testing. All CPE inserts developed subsurface cracks and delamination within 2.8 Mc during posterior edge loading fatigue studies, while none of the HXPE inserts showed cracking or delamination after 5 Mc. These results show that aged HXPE has higher wear and fatigue resistance than aged CPE, and offers potential long-term advantages for young active patients with sustained activities of daily living.

In vivo outcomes of tissue-engineered osteochondral grafts.

Tissue-engineered osteochondral grafts have been synthesized from a variety of materials, with some success at repairing chondral defects in animal models. We hypothesized that in tissue-engineered osteochondral grafts synthesized by bonding mesenchymal stem cell-loaded hydrogels to a porous material, the choice of the porous scaffold would affect graft healing to host bone, and the quality of cell restoration at the hyaline cartilage surface. Bone marrow-derived allogeneic mesenchymal stem cells were suspended in hydrogels that were attached to cylinders of porous tantalum metal, allograft bone, or a bioactive glass. The tissue-engineered osteochondral grafts, thus created were implanted into experimental defects in rabbit knees. Subchondral bone restoration, defect fill, bone ingrowth-implant integration, and articular tissue quality were compared between the three subchondral materials at 6 and 12 weeks. Bioactive glass and porous tantalum were superior to bone allograft in integrating to adjacent host bone, regenerating hyaline-like tissue at the graft surface, and expressing type II collagen in the articular cartilage.

Chitosan/polyglycolic acid nerve grafts for axon regeneration from prolonged axotomized neurons to chronically denervated segments.

Peripheral nerve regeneration for long-term delayed injuries is usually unsatisfied. Here we attempted to use a chitosan/polyglycolic acid (PGA) artificial nerve graft to bridge a long-term delayed 10-mm defect in SD rats based on the previous studies on the graft used for immediate repair of 30-mm-long dog sciatic nerve defects and for clinical treatment of a 35-mm-long median nerve defect at elbow of a human patient. In this study, for experimental groups, the rat sciatic nerve had been transected leaving a 10-mm defect, which was maintained for 3 or 6 months before implantation with the chitosan/PGA artificial nerve graft. The animals non-grafted or grafted with autograft served as negative or positive control group. In experiment groups, nerve regeneration with functional recovery was achieved as measured by electrophysiological and histological techniques, although differences in the quantity and the quality of the regenerated nerve were observed between the 3- and 6-month delayed subgroups. The results showed that: (1) a few denervated Schwann cells survived and sustained their ability to myelinate axons at least 6 months, and (2) the atrophic denervated muscle could be reinnervated by regenerated axons through new muscle-nerve connections. These observations provide the possibility of guiding regenerated axons from survived axotomized neurons to distal nerve stump by the chitosan/PGA artificial nerve graft.

Study of in vivo differentiation of rat bone marrow stromal cells into schwann cell-like cells.

In order to raise an abundant and accessible reservoir for Schwann cells (SCs), which are used as seed cells for constructing tissue-engineered nerve grafts, we investigated the feasibilty of in vivo differentiation of bone marrow stromal cells (MSCs) into SC-like cells. In this study, MSCs were harvested from adult rats' bone marrow, culture-expanded, and characterized. Subcultured MSCs were then labeled with Hoechst 33342, followed by transplantation into the nerve regeneration chamber, which was made of a silicone tube bridging the sciatic nerve defect of the rats. Four weeks after surgery, some of the differentiated MSCs turned into SC-like cells immunopositive to S-100 protein, accompanied by myelination of the regenerated nerve fibers. Walking-track analyses provided evidence that transplantation of MSCs contributed to reconstruction of the sciatic nerve and reinnervation of target tissues. The experimental results suggest that MSCs are capable of differentiating into SC-like cells in vivo, making them a promising candidate for cell transplantation in peripheral nerve repair.