Etiology, Pathogens, Clinical Features and Treatment of Bacterial Scleritis.

We retrospectively reviewed literature reports on pathogens, clinical features, diagnosis, treatment, and clinical and visual outcomes in patients with bacterial scleritis over the past decade. Eye surgery and trauma are the most common causes of bacterial infections. Subtenon triamcinolone acetonide injection, intravitreal ranibizumab, and wearing contact lenses are also causes of bacterial scleritis. Pseudomonas aeruginosa is the most common pathogenic microorganism causing bacterial scleritis. Mycobacterium tuberculosis ranks second. The main symptoms of bacterial scleritis are red and painful eyes. The patient's visual acuity decreased significantly. Bacterial scleritis caused by Pseudomonas aeruginosa often manifests as necrotizing scleritis, tuberculous scleritis and syphilitic scleritis are mostly nodular scleritis. Bacterial scleritis often involves the cornea, and approximately 37.6% (32 eyes) of patients had corneal bacterial infection. Hyphema was present in 18.8% (16 eyes). Elevated intraocular pressure was observed in 36.5% (31 eyes) of patients. Bacterial culture was an effective method of diagnosis. Most bacterial scleritis cases require both aggressive medical and surgical treatment, and the drug choice must be based on antibiotic susceptibility testing.

Structural Mechanical Properties of 3D Printing Biomimetic Bone Replacement Materials.

One of the primary challenges in developing bone substitutes is to create scaffolds with mechanical properties that closely mimic those of regenerated tissue. Scaffolds that mimic the structure of natural cancellous bone are believed to have better environmental adaptability. In this study, we used the porosity and thickness of pig cancellous bone as biomimetic design parameters, and porosity and structural shape as differential indicators, to design a biomimetic bone beam scaffold. The mechanical properties of the designed bone beam model were tested using the finite element method (FEM). PCL/ß-TCP porous scaffolds were prepared using the FDM method, and their mechanical properties were tested. The FEM simulation results were compared and validated, and the effects of porosity and pore shape on the mechanical properties were analyzed. The results of this study indicate that the PCL/ß-TCP scaffold, prepared using FDM 3D printing technology for cancellous bone tissue engineering, has excellent integrity and stability. Predicting the structural stability using FEM is effective. The triangle pore structure has the most stability in both simulations and tests, followed by the rectangle and honeycomb shapes, and the diamond structure has the worst stability. Therefore, adjusting the porosity and pore shape can change the mechanical properties of the composite scaffold to meet the mechanical requirements of customized tissue engineering.

Influence of Ag and/or Sr Dopants on the Mechanical Properties and In Vitro Degradation of ß-Tricalcium Phosphate-Based Ceramics.

ß-tricalcium phosphate has good biodegradability and biocompatibility; it is widely perceived as a good material for treating bone deficiency. In this research, different contents of strontium (Sr) and silver (Ag) ion-doped ß-tricalcium phosphate powders were prepared using the sol-gel method. After obtaining the best ratio of pore-forming agent and binder, the as-synthesized powders were sintered in a muffle for 5 h at 1000 °C to obtain the samples. Then, these samples were degraded in vitro in simulated body fluids. The samples were tested using a series of characterization methods before and after degradation. Results showed that the amount of Sr and/or Ag doping had an effect on the crystallinity and structural parameters of the samples. After degradation, though the compressive strength of these samples decreased overall, the compressive strength of the undoped samples was higher than that of the doped samples. Notably, apatite-like materials were observed on the surface of the samples. All the results indicate that Sr and/or Ag ß-TCP has good osteogenesis and proper mechanical properties; it will be applied as a prospective biomaterial in the area of bone repair.

Anti-Hu Antibody-Associated Adie's Pupil and Paraneoplastic Sensorimotor Polyneuropathy Caused by Primary Mediastinal Small Cell Carcinoma.

We report a woman with unilateral Adie's pupil associated with peripheral sensorimotor polyneuropathy, elevated anti-Hu antibody, and primary mediastinal small cell carcinoma (SCC). To our knowledge, this is the first report of Adie's pupil in a patient with mediastinal SCC. Although rare, Adie's pupil and sensorimotor polyneuropathy may be the first manifestation of cancer. Its rapid recognition facilitates an early diagnosis and treatment.

Characterization of silane treated and untreated natural cellulosic fibre from corn stalk waste as potential reinforcement in polymer composites.

Natural cellulosic fibres have significant potential as reinforcements to replace synthetic fibres applied in biopolymer composites. A natural cellulosic fibre was extracted from corn stalk waste and then it was treated by silane solution with different concentrations. The influences of silane on chemical, surface morphological and mechanical performances of Corn Stalk Fibre (CSF) as well as impact strength and impact fracture surface morphology of CSF reinforced polymer composites were evaluated in the present work. The chemical results showed that silane treatments remove a certain amount of hemicelluloses and lignin from the CSF surface, and increase the Crystallinity Index (CrI) and Crystalline Size (CrS) of the CSF. The CSF treated with 5 wt.% silane solution (5%STCF) presents a highest tensile strength of 223.33 MPa ± 41.22 MPa and Young's modulus of 18.98 GPa ± 2.43 GPa. The silane treatments can also improve the fibre-matrix interfacial bonding and enhance the impact strength of the polymer composites. The surface morphologies of the untreated and treated natural fibres and the impact fracture surface of the composites were examined by SEM.

Human umbilical cord blood-derived stem cells and brain-derived neurotrophic factor protect injured optic nerve: viscoelasticity characterization.

The optic nerve is a viscoelastic solid-like biomaterial. Its normal stress relaxation and creep properties enable the nerve to resist constant strain and protect it from injury. We hypothesized that stress relaxation and creep properties of the optic nerve change after injury. More-over, human brain-derived neurotrophic factor or umbilical cord blood-derived stem cells may restore these changes to normal. To validate this hypothesis, a rabbit model of optic nerve injury was established using a clamp approach. At 7 days after injury, the vitreous body re-ceived a one-time injection of 50 µg human brain-derived neurotrophic factor or 1 × 10(6) human umbilical cord blood-derived stem cells. At 30 days after injury, stress relaxation and creep properties of the optic nerve that received treatment had recovered greatly, with patho-logical changes in the injured optic nerve also noticeably improved. These results suggest that human brain-derived neurotrophic factor or umbilical cord blood-derived stem cell intervention promotes viscoelasticity recovery of injured optic nerves, and thereby contributes to nerve recovery.

Human umbilical cord blood stem cells and brain-derived neurotrophic factor for optic nerve injury: a biomechanical evaluation.

Treatment for optic nerve injury by brain-derived neurotrophic factor or the transplantation of human umbilical cord blood stem cells has gained progress, but analysis by biomechanical indicators is rare. Rabbit models of optic nerve injury were established by a clamp. At 7 days after injury, the vitreous body received a one-time injection of 50 µg brain-derived neurotrophic factor or 1 × 10(6) human umbilical cord blood stem cells. After 30 days, the maximum load, maximum stress, maximum strain, elastic limit load, elastic limit stress, and elastic limit strain had clearly improved in rabbit models of optical nerve injury after treatment with brain-derived neurotrophic factor or human umbilical cord blood stem cells. The damage to the ultrastructure of the optic nerve had also been reduced. These findings suggest that human umbilical cord blood stem cells and brain-derived neurotrophic factor effectively repair the injured optical nerve, improve biomechanical properties, and contribute to the recovery after injury.