21 research outputs found

    3D bioactive composite scaffolds for bone tissue engineering

    Get PDF
    Bone is the second most commonly transplanted tissue worldwide, with over four million operations using bone grafts or bone substitute materials annually to treat bone defects. However, significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma, cancer, infection and arthritis. Developing bioactive three-dimensional (3D) scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering (BTE). A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts. However, individual groups of materials including polymers, ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone. Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds. This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers, hydrogels, metals, ceramics and bio-glasses in BTE. Scaffold fabrication methodology, mechanical performance, biocompatibility, bioactivity, and potential clinical translations will be discussed

    Cutaneous Type of Nocardiosis Caused by Nocardia brasiliensis in an Elderly Patient

    No full text
    Acute soft tissue infection with Nocardia brasiliensis is an uncommon manifestation in the elderly. A case of cellulitis and an abscess on the foot due to N. brasiliensis in a 77-year-old man with chronic obstructive pulmonary disease is reported. N. brasiliensis was isolated from fluid from the bulla. Treatment with trimethoprim–sulfamethoxazole for 6 months led to complete resolution and no evidence of recurrence was noted. Nocardia infection must be considered in the differential diagnosis for elderly patients with soft tissue infection, especially in those with severe underlying diseases, and we suggest that trimethoprim–sulfamethoxazole is an effective and safe treatment

    Altered oscillation and synchronization of default-mode network activity in mild Alzheimer's disease compared to mild cognitive impairment: an electrophysiological study.

    Get PDF
    Some researchers have suggested that the default mode network (DMN) plays an important role in the pathological mechanisms of Alzheimer's disease (AD). To examine whether the cortical activities in DMN regions show significant difference between mild AD from mild cognitive impairment (MCI), electrophysiological responses were analyzed from 21 mild Alzheimer's disease (AD) and 21 mild cognitive impairment (MCI) patients during an eyes closed, resting-state condition. The spectral power and functional connectivity of the DMN were estimated using a minimum norm estimate (MNE) combined with fast Fourier transform and imaginary coherence analysis. Our results indicated that source-based EEG maps of resting-state activity showed alterations of cortical spectral power in mild AD when compared to MCI. These alterations are characteristic of attenuated alpha or beta activities in the DMN, as are enhanced delta or theta activities in the medial temporal, inferior parietal, posterior cingulate cortex and precuneus. With regard to altered synchronization in AD, altered functional interconnections were observed as specific connectivity patterns of connection hubs in the precuneus, posterior cingulate cortex, anterior cingulate cortex and medial temporal regions. Moreover, posterior theta and alpha power and altered connectivity in the medial temporal lobe correlated significantly with scores obtained on the Mini-Mental State Examination (MMSE). In conclusion, EEG is a useful tool for investigating the DMN in the brain and differentiating early stage AD and MCI patients. This is a promising finding; however, further large-scale studies are needed

    Correlation between MMSE and normalized spectral power in the brain regions of DMN.

    No full text
    <p>ROI, region of interest; L, left hemisphere; R, right hemisphere; MFC, media frontal cortex; ACC, anterior cingulate cortex; MT, medial temporal; IP, inferior parietal cortex; PCC, posterior cingulate cortex; PCu, precuneus;</p>*<p>p<0.05;</p>**<p>p<0.01.</p

    Significant differences of functional connectivity within the DMN with respect to different frequency bands between AD and MCI.

    No full text
    <p>The solid line indicates larger IC values between brain regions in MCI, and the dotted line exhibits larger ones in AD. Scatter plots with linear regression represent the correlation between MMSE scores and IC values. *, p<0.05; **, p<0.01; ***.</p

    Demographic information of AD and MCI subjects.

    No full text
    <p>IAF, individual alpha frequency; CDR, clinical dementia rating; MMSE, mini-mental state estimate.</p

    Frameless versus frame-based stereotactic radiosurgery for intracranial arteriovenous malformations: A propensity-matched analysis

    No full text
    Objective: The frameless linear accelerator (LINAC) based stereotactic radiosurgery (SRS) has been evolving with a reduction in patient discomfort. However, there was limited evidence comparing frame-based and frameless SRS for intracranial arteriovenous malformations (AVM). We aimed to compare the treatment outcomes between frame-based and frameless LINAC SRS. Materials and Methods: This retrospective cohort compared the outcomes of frame-based LINAC SRS (1998–2009) with frameless LINAC SRS (2010–2020). The primary outcome was the obliteration rate. The other outcomes included the neurological, radiological, and functional outcomes after SRS. A matched cohort was identified by propensity scores for further comparisons. Results: A total of 65 patients were included with a mean follow-up time of 13.2 years (158.5 months). There were 40 patients in the frame-based group and 25 patients in the frameless group. The overall obliteration rate was comparable (Frame-based 82.5% vs Frameless 80.0%, p = 0.310) and not significantly different over time (log-rank p = 0.536). The crude post-SRS hemorrhage rate was 1.5% and the incidence was 0.3 per 100 person-years. There were 67.7% of patients with AVM obliteration without new persistent neurological deficits at the last visit and 56.9% of patients with AVM obliteration without any deficits (transient or persistent) during the entire follow-up period. Four patients (8.0%) developed late onset persistent adverse radiation effects (more than 96 months after SRS) among 50 patients with more than 8-year surveillance. In the propensity-matched cohort of 42 patients, there was no significant difference in AVM obliteration (Frame-based vs Frameless, log-rank p = 0.984). Conclusion: Frameless and frame-based LINAC SRS have comparable efficacy in intracranial AVM obliteration. A longer follow-up duration may further characterize the rate of late adverse radiation effects in frameless SRS
    corecore