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1.
ACS Sens ; 2024 May 29.
Article in English | MEDLINE | ID: mdl-38810251

ABSTRACT

Bacterial infections lack reliable, specific, and quick detection methods, which incur substantial costs to patients and caretakers. Our team conjugated the FDA-approved fluorescent dye indocyanine green (ICG) with a maltotriose sugar, resulting in two highly specific imaging agents (ICG-DBCO-1-Maltotriose and ICG-Amide-1-Maltotriose) for detecting bacterial infections. We then evaluated the two derivatives using fluorescence imaging (FLI), bioluminescence imaging (BLI), and photoacoustic imaging (PAI) in bacterial infection murine models. Our findings indicate that both imaging agents can correlate with and reliably detect the infection site using FLI and PAI for both Gram-negative and Gram-positive strains, with various bacterial loads. Furthermore, the differences in pharmacokinetic (PK) properties between the two agents allow for one to be used for immediate imaging (2-4 h postinjection), while the other is more effective for longitudinal studies (18-40 h postinjection).

2.
Gerodontology ; 41(1): 141-148, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37792413

ABSTRACT

OBJECTIVES: To explore the effects and improvement needs of an outreach dental care programme (ODCP) for older adults using residential care or daycare services from the perspectives of the caregivers, the dentists and administrative staff involved in the implementation of the ODCP. METHODS: A qualitative study was conducted through semi-structured interviews with three stakeholders, long-term care (LTC) facility caregivers, administrative staff and dentists working for the ODCP. Combined maximum variation and snowball sampling strategies were adopted, and 22, 9 and 7 participants were interviewed from each stakeholder, respectively. The interviews were conducted via telephone, which were audio-recorded and transcribed verbatim for analysis. NVivo software was used for storing and analysing the data. Data analysis was conducted continuously during the study. RESULTS: Most participants opined that the ODCP benefited older adults by raising their oral health conditions and awareness. However, they complained of the complicated administrative procedures, unmet dental treatment needs, inefficient coordination, unclear work guidelines and shortage of dental manpower. More advanced dental treatment options, better coordination among different parties, simpler administrative processes and better incentives for dentists were proposed to further improve the programme. CONCLUSIONS: According to the stakeholders, ODCP seems beneficial to older adults using LTC services. Further improvements in the scope of dental treatments, cooperation between the outreach dental teams and caregivers, and streamlining of the administrative process are needed for the provision of effective outreach dental care to satisfy the unmet treatment needs of older adults who use LTC services. Better incentives are needed to attract and retain dentists.


Subject(s)
Long-Term Care , Mouth Diseases , Humans , Aged , Hong Kong , Nursing Homes , Qualitative Research , Dental Care
3.
J Biomed Opt ; 28(6): 066003, 2023 06.
Article in English | MEDLINE | ID: mdl-37334207

ABSTRACT

Significance: Cholesteatoma is an expansile destructive lesion of the middle ear and mastoid, which can result in significant complications by eroding adjacent bony structures. Currently, there is an inability to accurately distinguish cholesteatoma tissue margins from middle ear mucosa tissue, causing a high recidivism rate. Accurately differentiating cholesteatoma and mucosa will enable a more complete removal of the tissue. Aim: Develop an imaging system to enhance the visibility of cholesteatoma tissue and margins during surgery. Approach: Cholesteatoma and mucosa tissue samples were excised from the inner ear of patients and illuminated with 405, 450, and 520 nm narrowband lights. Measurements were made with a spectroradiometer equipped with a series of different longpass filters. Images were obtained using a red-green-blue (RGB) digital camera equipped with a long pass filter to block reflected light. Results: Cholesteatoma tissue fluoresced under 405 and 450 nm illumination. Middle ear mucosa tissue did not fluoresce under the same illumination and measurement conditions. All measurements were negligible under 520 nm illumination conditions. All spectroradiometric measurements of cholesteatoma tissue fluorescence can be predicted by a linear combination of emissions from keratin and flavin adenine dinucleotide. We built a prototype of a fluorescence imaging system using a 495 nm longpass filter in combination with an RGB camera. The system was used to capture calibrated digital camera images of cholesteatoma and mucosa tissue samples. The results confirm that cholesteatoma emits light when it is illuminated with 405 and 450 nm, whereas mucosa tissue does not. Conclusions: We prototyped an imaging system that is capable of measuring cholesteatoma tissue autofluorescence.


Subject(s)
Cholesteatoma, Middle Ear , Humans , Cholesteatoma, Middle Ear/diagnostic imaging , Cholesteatoma, Middle Ear/surgery , Cholesteatoma, Middle Ear/pathology , Ear, Middle/pathology , Mucous Membrane/pathology , Mastoid/pathology , Mastoid/surgery , Optical Imaging
4.
J Biomed Opt ; 28(9): 094803, 2023 09.
Article in English | MEDLINE | ID: mdl-37188003

ABSTRACT

Significance: Cerebrospinal fluid (CSF) rhinorrhea (leakage of brain fluid from the nose) can be difficult to identify and currently requires invasive procedures, such as intrathecal fluorescein, which requires a lumbar drain placement. Fluorescein is also known to have rare but significant side effects including seizures and death. As the number of endonasal skull base cases increases, the number of CSF leaks has also increased for which an alternative diagnostic method would be highly advantageous to patients. Aim: We aim to develop an instrument to identify CSF leaks based on water absorption in the shortwave infrared (SWIR) without the need of intrathecal contrast agents. This device needed to be adapted to the anatomy of the human nasal cavity while maintaining low weight and ergonomic characteristics of current surgical instruments. Approach: Absorption spectra of CSF and artificial CSF were obtained to characterize the absorption peaks that could be targeted with SWIR light. Different illumination systems were tested and refined prior to adapting them into a portable endoscope for testing in 3D-printed models and cadavers for feasibility. Results: We identified CSF to have an identical absorption profile as water. In our testing, a narrowband laser source at 1480 nm proved superior to using a broad 1450 nm LED. Using a SWIR enabling endoscope set up, we tested the ability to detect artificial CSF in a cadaver model. Conclusions: An endoscopic system based on SWIR narrowband imaging can provide an alternative in the future to invasive methods of CSF leak detection.


Subject(s)
Cerebrospinal Fluid Leak , Cerebrospinal Fluid Rhinorrhea , Humans , Cerebrospinal Fluid Leak/surgery , Cerebrospinal Fluid Rhinorrhea/surgery , Endoscopy/methods , Skull Base/diagnostic imaging , Skull Base/surgery , Fluorescein , Retrospective Studies
5.
Community Dent Oral Epidemiol ; 51(5): 945-952, 2023 10.
Article in English | MEDLINE | ID: mdl-36111654

ABSTRACT

AIM: To evaluate the effects of an outreach dental care program (ODCP) on the oral health status and oral health-related quality of life (OHRQoL) of older adults who used residential or day care services in Hong Kong. METHODS: Older adults who had received dental treatments provided in the ODCP were recruited. Clinical examinations were performed by one calibrated examiner (SXY) at baseline and 1-year follow-up in the residential homes or day care centres. Face-to-face interviews were conducted using the transition scale of the Oral Health Impacts on Daily Living (OHIDL) questionnaire to investigate the perceived change in OHRQoL at baseline, 2-month and 1-year follow-ups. The Wilcoxon matched-pair signed-rank test or McNemar/McNemar-Bowker test was used to explore the change in oral health status after dental treatments. Factors associated with the perceived change in OHRQoL were explored with binary logistic regression. RESULTS: Four hundred and thirteen older adults (mean age = 83.8 years) participated in the study at baseline, and 377 (91.3%) and 359 (86.9%) were successfully followed 2 months and 1 year after receiving the outreach dental service, respectively. At the 1-year follow-up, the number of decayed teeth and functional tooth units, and the prevalence of poor denture hygiene decreased while there was more dental plaque deposition and a higher proportion of participants with gingival bleeding upon probing. More than 50% of the participants perceived no change or an improvement in OHRQoL in all domains at both follow-ups. Older adults who perceived their oral health status as 'healthy or fair' and those who suffered from toothache at baseline had a higher chance to perceive having a better or at least the same OHRQoL at the 2-month and 1-year follow-ups, respectively. CONCLUSIONS: The ODCP in Hong Kong can solve some of the dental problems of older adults using long-term care services and keep most of them from deterioration in OHRQoL, especially those suffering from toothache.


Subject(s)
Quality of Life , Toothache , Humans , Aged , Aged, 80 and over , Cohort Studies , Hong Kong/epidemiology , Day Care, Medical , Oral Health , Dental Care
6.
ACS Appl Bio Mater ; 5(10): 4849-4859, 2022 10 17.
Article in English | MEDLINE | ID: mdl-36179346

ABSTRACT

We present a topical drug delivery mechanism through the ear canal to the middle and inner ear using liposomal nanoparticles without disrupting the integrity of the tympanic membrane. The current delivery method provides a noninvasive and safer alternative to transtympanic membrane injections, ear tubes followed by ear drops administration, and systemic drug formulations. We investigate the capability of liposomal NPs, particularly transfersomes (TLipo), used as drug delivery vesicles to penetrate the tympanic membrane (TM) and round window membrane (RWM) with high affinity, specificity, and retention time. The TLipo is applied to the ear canal and found to pass through the tympanic membrane quickly in 3 h post drug administration. They are identified in the middle ear cavity 6 h and in the inner ear 24 h after drug administration. We performed cytotoxicity in vitro and ototoxicity in vivo studies. Cell viability shows no significant difference between the applied TLipo concentration and control. Furthermore, auditory brainstem response (ABR) reveals no hearing loss in 1 week and 1 month post-administration. Immunohistochemistry results demonstrate no evidence of hair cell loss in the cochlea at 1 month following TLipo administration. Together, the data suggested that TLipo can be used as a vehicle for topical drug delivery to the middle ear and inner ear.


Subject(s)
Ear Diseases , Ear, Inner , Labyrinth Diseases , Cochlea , Drug Delivery Systems , Ear Diseases/drug therapy , Humans , Round Window, Ear/physiology
7.
Am J Orthod Dentofacial Orthop ; 160(6): 872-886, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34392988

ABSTRACT

A patient with mutilated dentition was treated to an acceptable result with the help of mini-implants for anchorage, autotransplantation of 2 teeth, one dental implant, and multiple prostheses. The major problems for this mutilated dentition were multiple missing teeth, bite collapse with posterior crossbites, deepbite with a canted gummy smile, and severe skeletal discrepancy of maxillary protrusion and mandibular retrusion. Mini-implant anchorage was applied to retract and intrude the maxillary arch to reduce the protrusion and rotate the mandible counterclockwise to improve the chin projection. Two autotransplantations, one dental implant, and multiple prostheses were used to accomplish a satisfactory full mouth rehabilitation with an interdisciplinary approach, including orthodontics, periodontics, endodontics, prosthodontics, and implantology. The understanding of biological principles, improvement in surgical protocol makes it possible to preserve the periodontal ligament (PDL) cells with atraumatic extraction after loosening the donor with orthodontic force and reduce the extraoral time with the 3-dimensional print-out replica segmented from cone-beam computed tomography for trying fitness. Soft wire splinting to gain initial stabilization and root canal treatment to avoid endotoxin further reduce the risk of root resorption, loss of attachment, and ankylosis. Autotransplantation could be considered as a part of full mouth rehabilitation. Orthodontic space management is also an important procedure to confirm the site of dental implant installation in the interdisciplinary collaboration.


Subject(s)
Dental Implants , Malocclusion, Angle Class II , Orthodontic Anchorage Procedures , Autografts , Cephalometry , Dentition , Esthetics, Dental , Gingiva , Humans , Smiling , Transplantation, Autologous
8.
Healthcare (Basel) ; 9(4)2021 Apr 01.
Article in English | MEDLINE | ID: mdl-33915802

ABSTRACT

Hong Kong has a large and growing population of older adults but their oral health conditions and utilization of dental services are far from optimal. To reduce the financial barriers and to improve the accessibility of dental care services to the older adults, a number of programmes adopting an innovative shared funding, administration, and provision mode have recently been implemented. In this review, an online search on the Hong Kong government websites and the electronic medical literature databases was conducted using keywords such as "dental care," "dental service," and "Hong Kong." Dental care services for older adults in Hong Kong were identified. These programmes include government-funded outreach dental care service provided by non-governmental organizations (NGOs), provision of dentures and related treatments by private and NGO dentists supported by the Community Care Fund, and government healthcare vouchers for private healthcare, including dental, services. This paper presents the details of the operation of these programmes and the initial findings. There is indirect evidence that these public-funded dental care service programmes have gained acceptance and support from the government, the service recipients, and the providers. The experience gained is of great value for the development of appropriate dental care services for the older adults in Hong Kong and worldwide.

9.
Front Oral Health ; 2: 703526, 2021.
Article in English | MEDLINE | ID: mdl-35048040

ABSTRACT

The aim of this study was to present a concise summary of the oral health policies and oral healthcare schemes for older adult populations in a number of selected countries around the world. In this paper, the current and planned national/regional oral health policies and oral healthcare schemes of nine countries (Australia, Brazil, China including Hong Kong, India, Japan, Switzerland, Thailand, the United Kingdom, and the United States) are reported. Barriers and challenges in oral health promotion in terms of devising oral health policies, implementing oral health schemes, and educating the future dental workforce are discussed. In response to the aging of population, individual countries have initiated or reformed their healthcare systems and developed innovative approaches to deliver oral health services for older adults. There is a global shortage of dentists trained in geriatric dentistry. In many countries, geriatric dentistry is not formally recognized as a specialty. Education and training in geriatric dentistry is needed to produce responsive and competent dental professionals to serve the increasing number of older adults. It is expected that oral health policies and oral healthcare services will be changing and reforming in the coming decades to tackle the enduring oral health challenges of aging societies worldwide.

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