Tunable In Situ Synthesis of Ultrathin Extracellular Matrix-Derived Membranes in Organ-on-a-Chip Devices.

Thin cell culture membranes in organ-on-a-chip (OOC) devices are used to model a wide range of thin tissues. While early and most current platforms use microporous or fibrous elastomeric or thermoplastic membranes, there is an emerging class of devices using extra-cellular matrix (ECM) protein-based membranes to improve their biological relevance. These ECM-based membranes present physiologically relevant properties, but they are difficult to integrate into OOC devices due to their relative fragility. Additionally, the specialized fabrication methods developed to date make comparison between methods difficult. This work presents the development and characterization of a method to produce ultrathin matrix-derived membranes (UMM) in OOC devices that requires only a preassembled thermoplastic device and a micropipette, decoupling the device and UMM fabrication processes. Control over the thickness and permeability of the UMM is demonstrated, along with integration of the UMM in a device enabling high-resolution on-chip microscopy. The reliability of the UMM fabrication method is leveraged to develop a medium-throughput well-plate format device with 32 independent UMM-integrated samples. Finally, proof-of-concept cell culture experiments are demonstrated. Due to its simplicity and controllability, the presented method has the potential to overcome technical barriers preventing wider adoption of physiologically relevant ECM-based membranes in OOC devices.

Collagen Tubular Airway-on-Chip for Extended Epithelial Culture and Investigation of Ventilation Dynamics.

The lower respiratory tract is a hierarchical network of compliant tubular structures that are made from extracellular matrix proteins with a wall lined by an epithelium. While microfluidic airway-on-a-chip models incorporate the effects of shear and stretch on the epithelium, week-long air-liquid-interface culture at physiological shear stresses, the circular cross-section, and compliance of native airway walls have yet to be recapitulated. To overcome these limitations, a collagen tube-based airway model is presented. The lumen is lined with a confluent epithelium during two-week continuous perfusion with warm, humid air while presenting culture medium from the outside and compensating for evaporation. The model recapitulates human small airways in extracellular matrix composition and mechanical microenvironment, allowing for the first time dynamic studies of elastocapillary phenomena associated with regular breathing and mechanical ventilation, as well as their impacts on the epithelium. A case study reveales increasing damage to the epithelium during repetitive collapse and reopening cycles as opposed to overdistension, suggesting expiratory flow resistance to reduce atelectasis. The model is expected to promote systematic comparisons between different clinically used ventilation strategies and, more broadly, to enhance human organ-on-a-chip platforms for a variety of tubular tissues.

A ketogenic diet rich in fish oil is superior to other fats in preventing NNK-induced lung cancer in A/J mice.

Given that ketogenic diets (KDs) are extremely high in dietary fat, we compared different fats in KDs to determine which was the best for cancer prevention. Specifically, we compared a Western and a 15% carbohydrate diet to seven different KDs, containing either Western fats or fats enriched in medium chain fatty acids (MCTs), milk fat (MF), palm oil (PO), olive oil (OO), corn oil (CO) or fish oil (FO) for their ability to reduce nicotine-derived nitrosamine ketone (NNK)-induced lung cancer in mice. While all the KDs tested were more effective at reducing lung nodules than the Western or 15% carbohydrate diet, the FO-KD was most effective at reducing lung nodules. Correlating with this, mice on the FO-KD had low blood glucose and the highest ß-hydroxybutyrate level, lowest liver fatty acid synthase/carnitine palmitoyl-1a ratio and a dramatic increase in fecal Akkermansia. We found no liver damage induced by the FO-KD, while the ratio of total cholesterol/HDL was unchanged on the different diets. We conclude that a FO-KD is superior to KDs enriched in other fats in reducing NNK-induced lung cancer, perhaps by being the most effective at skewing whole-body metabolism from a dependence on glucose to fats as an energy source.

Porocarcinoma of the Left Foot: A Case Review.

Eccrine porocarcinoma is a rare malignant tumor of the eccrine sweat gland. This malignancy occurs most commonly in the lower extremities. It tends to occur in patients aged 60 to 80 years, affecting men and women equally. We present the case of a 62-year-old man with a lesion on the left foot. The diagnosis of the initial biopsy was squamous cell carcinoma. Six months later, the lesion reoccurred, and a second biopsy confirmed it to be eccrine porocarcinoma.

A Cell-Based Optimised Approach for Rapid and Efficient Gene Editing of Human Pluripotent Stem Cells.

Introducing or correcting disease-causing mutations through genome editing in human pluripotent stem cells (hPSCs) followed by tissue-specific differentiation provide sustainable models of multiorgan diseases, such as cystic fibrosis (CF). However, low editing efficiency resulting in extended cell culture periods and the use of specialised equipment for fluorescence activated cell sorting (FACS) make hPSC genome editing still challenging. We aimed to investigate whether a combination of cell cycle synchronisation, single-stranded oligodeoxyribonucleotides, transient selection, manual clonal isolation, and rapid screening can improve the generation of correctly modified hPSCs. Here, we introduced the most common CF mutation, ΔF508, into the CFTR gene, using TALENs into hPSCs, and corrected the W1282X mutation using CRISPR-Cas9, in human-induced PSCs. This relatively simple method achieved up to 10% efficiency without the need for FACS, generating heterozygous and homozygous gene edited hPSCs within 3-6 weeks in order to understand genetic determinants of disease and precision medicine.

Factors affecting timeliness in management of head and neck cancer.

BACKGROUND: Timeliness in the management of patients with head and neck cancer (HNC) can be affected by both patient and non-patient related factors. This study aims to investigate the factors associated with the timeliness of managing HNC. METHODS: A retrospective review was conducted on Western Health medical records including all new patients presenting to the Western Health HNC surgical outpatient clinic in the five-year period from first January 2017 to 31st December 2021 with the diagnosis of a HNC. Both patient and non-patient related factors were compared with the duration between a patient's referral to a HNC service and the commencement of their treatment. RESULTS: Two hundred and twenty-eight patients were included in this study. The median duration from referral to the commencement of treatment was 48 days. Lack of radiological or pathological investigations prior to referral to a HNC service as well as early staging were found to significantly impact timeliness in management. Socioeconomic factors such as non-English speaking backgrounds, distance from the hospital and lack of social supports were not found to negatively impact timeliness of management. CONCLUSION: The management of patients with HNC require careful consideration of all patient and non-patient related factors which may affect timeliness in management, particularly investigations performed prior to their referral to a HNC service.

Mobility and Hip Function Among Geriatric Patients With Displaced Neck of Femur Fractures Treated With Arthroplasty.

Background: Neck of femur fractures result in impaired function for older people. Despite surgery, many patients experience a decrease in functional level and poorer health status after the injury. The objectives of this study were (1) to determine the short-term mobility and hip function of geriatric patients who underwent hip replacement surgery for a displaced neck of femur fracture in our local population and (2) to identify factors which affect the functional outcome of these patients. Methods: Patients aged 60 years and above, who were admitted for neck of femur fracture from January 2017 to December 2020, and treated surgically with arthroplasty, were included. Information on patient demography, comorbidities, perioperative data, mobility, hip function and complications were retrospectively collected. Outcome measures used were independent ambulation and recovery of pre-fracture mobility at 1 year after surgery while hip function was assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total, pain, stiffness, and physical function scores. Factors associated with these outcomes were analyzed. Results: 168 patients with a mean age of 75.2 (SD 8.4) years met the inclusion criteria. 32.1% of patients regained their pre-fracture mobility and 59.6% remained independent 1 year after surgery. Logistic regression analysis identified age, gender, surgical procedure, and time to surgery as significant contributors to recovery of pre-fracture mobility. Older age and increasing requirement for postoperative ambulatory aid resulted in worse WOMAC total and physical function scores. No significant differences were observed in patient-reported hip function between those who had a total hip arthroplasty and those who had a hemiarthroplasty. Conclusion: Most geriatric patients with displaced neck of femur fractures did not regain pre-fracture mobility despite surgical treatment with arthroplasty.

Improving prenatal detection of abdominal supraumbilical anomalies: The sonographic examination of fetal anechoic spaces of upper abdomen revisited.

Visualization of the axial plane of the fetal abdomen is mandatory to obtain abdominal biometry in the assessment of fetal growth in the second and third trimesters. The main anatomic landmarks that must be identified in this view include the fetal stomach and the intrahepatic portion of the umbilical vein, which are easily identifiable as they appear anechoic on ultrasound. The gallbladder is the other prominent anechoic structure in this plane. Focused study of the morphological characteristics of, and spatial relationship among, these three anechoic spaces is a simple technique to detect anomalies involving fetal upper abdominal organs. In this review, the sonographic features of those conditions that can be detected using this technique, which was termed the Fetal Examination of the Anechoic Spaces of upper abdomen Technique (FEAST), are classified and illustrated.

Challenge-Based Learning in Dental Education.

Challenge-based learning (CBL) is a novel learning framework for a collaborative and multidisciplinary learning experience. It allows students, teachers, stakeholders, researchers, families, and society to work together to identify and solve real-world challenges. CBL helps students develop a deeper knowledge of the subjects they are studying. The concepts of CBL originate from a variety of educational theories and approaches, such as problem-based learning and inquiry-based learning. The precursor to the CBL framework is problem-based learning. However, unlike in problem-based learning and other approaches, students formulate the challenges they will address in CBL. Furthermore, students need to create a solution resulting in concrete action. CBL takes into account the social impact of an idea rather than just the corporate benefits. Therefore, it can help students expand the scope and depth of learning, encourage teamwork capabilities, and raise their awareness about considering quality and ethics in decision-making. CBL is implemented in universities, schools, and institutions worldwide and its use is well-recognized in science, engineering, and medicine, but it has not been translated into dentistry. The aim of this paper is to describe the concept of inclusion, principles and design, implementation, and supervision of the CBL framework in a dental course for the adaption of this learning framework to dental education.

Update on Dental Luting Materials.

A dental luting material aids in the retention and stability of indirect restorations on the prepared tooth structure. In dentistry, clinicians are using a wide range of luting materials for the cementation of indirect restorations. Zinc oxide eugenol and non-eugenol cements, zinc phosphate cement, zinc polycarboxylate cement, glass ionomer cement and resin cements are common dental cements used in dentistry. Each luting material or cement possesses unique properties and clinical implications. An ideal luting cement should be biocompatible, insoluble, resistant to thermal and chemical assaults, antibacterial, aesthetic, simple and easy to use. It should have high strength properties under tension, shear and compression to resist stress at the restoration-tooth interface, as well as adequate working and setting times. So far, no luting material possesses all of these properties of an ideal cement. Scientists have been modifying the conventional luting cements to improve the material's clinical performance and developing novel materials for clinical use. To achieve the best clinical outcome, clinicians should update their knowledge and gain a good understanding of the luting materials so that they can make a wise clinical decision on the material selection and obtain an insight into the development of luting cements. Therefore, the objective of this study is to provide a discussion on the physical, chemical, adhesive and aesthetic properties of common luting materials. The clinical indications of these luting materials are suggested based on their properties. In addition, overviews of the modification of the conventional luting materials and the newly developed luting materials are provided.

An assessment of people living by coral reefs over space and time.

Human populations near ecosystems are used as both a proxy for dependency on ecosystems, and conversely to estimate threats. Consequently, the number of people living near coral reefs is often used in regional coral reef management, evaluation of risk at regional and global scales, and even considerations of funding needs. Human populations and their statistics, are ever-changing and data relating to coral reefs have not been updated regularly. Here, we present an up-to-date analysis of the abundance, and density of people living within 5-100 km of coral reef ecosystems along with population proportion, using freely available data sets and replicable methods. We present trends of changes in human populations living near coral reefs over a 20-year time period (2000-2020), divided by region and country, along with socio-economic denominations such as country income category and Small Island Developing States (SIDS). We find that across 117 coral reef countries there are currently close to a billion people living within 100 km of a coral reef (~13% of the global population) compared with 762 million people in 2000. Population growth by coral reefs is higher than global averages. The Indian Ocean saw a 33% increase in populations within 100 km of a coral reef and 71% at 5 km. There are 60 countries with 100% of their population within 100 km of coral reefs. In SIDS, the proportion of the total population within 100 km of a coral reef is extremely high: 94% in 2020. Population density 5-10 km from coral reefs is 4× the global average. From 5 to 100 km, more people from lower-middle-income countries live by coral reefs than any other income category. Our findings provide the most up-to-date and extensive statistics on the regional and nation-level differences in population trends that play a large role in coral reef health and survival.

Tunnel Restoration: A Minimally Invasive Dentistry Practice.

With advances in technology, dentists nowadays manage dental caries with the philosophy of minimally invasive dentistry. Dental restoration is now performed most conservatively with minimal destruction of tooth structure when operative dentistry is indicated. Some operative dentists suggested using tunnel restoration for treating proximal caries as a conservative alternative to the conventional box preparation. The main advantage of tunnel restoration over the conventional box or slot preparation includes being more conservative and increasing tooth integrity and strength by preserving the marginal ridge. However, tunnel restoration is technique sensitive and requires advanced operative skills. Tunnel restoration can be an option to restore proximal caries if the dentist selects the proper case and pays attention to the details of the restorative procedures. With the dentist's advanced training, advanced light-emitting diode handpieces, magnifying loupes, precise digital imaging and new generation restorative materials, good results can be obtained in selected cases. This study reviews the literature on tunnel restoration and provides updated techniques and clinical data that can be used in tunnel restoration to oversee its limitations and the perspective on restorative treatment.

Modulation of DNA methylation and protein expression in the prefrontal cortex by repeated administration of D-lysergic acid diethylamide (LSD): Impact on neurotropic, neurotrophic, and neuroplasticity signaling.

AIM: Psychedelic compounds elicit relief from mental disorders. However, the underpinnings of therapeutic improvement remain poorly understood. Here, we investigated the effects of repeated lysergic acid diethylamide (LSD) on whole-genome DNA methylation and protein expression in the mouse prefrontal cortex (PFC). METHODS: Whole genome bisulphite sequencing (WGBS) and proteomics profiling of the mouse prefrontal cortex (PFC) were performed to assess DNA methylation and protein expression changes following 7 days of repeated LSD administration (30 µg/kg/day); a treatment we previously found to potentiate excitatory neurotransmission and to increase dendritic spine density in the PFC in mice. qRT-PCR was employed to validate candidate genes detected in both analyses. RESULTS: LSD significantly modulated DNA methylation in 635 CpG sites of the mouse PFC, and in an independent cohort the expression level of 178 proteins. Gene signaling pathways affected are involved in nervous system development, axon guidance, synaptic plasticity, quantity and cell viability of neurons and protein translation. Four genes and their protein product were detected as differentially methylated and expressed, and their transcription was increased. Specifically, Coronin 7 (Coro7), an axon guidance cue; Penta-EF-Hand Domain Containing 1 (Pef1), an mTORC1 and cell cycle modulator; Ribosomal Protein S24 (Rps24), required for pre-rRNA maturation and biogenesis of proteins involved with cell proliferation and migration, and Abhydrolase Domain Containing 6, Acylglycerol Lipase (Abhd6), a post-synaptic lipase. CONCLUSIONS: LSD affects DNA methylation, altering gene expression and protein expression related to neurotropic-, neurotrophic- and neuroplasticity signaling. This could represent a core mechanism mediating the effects of psychedelics.

Molecular Epidemiology of Human Papillomavirus Infection Among Chinese Women With Cervical Cytological Abnormalities.

Background: Virtually all invasive cervical cancers are caused by persistent genital human papillomavirus (HPV) infection. Therefore, HPV-based screening becomes an essential tool as one of the cervical prevention strategies to reduce the disease burden. Population-specific epidemiologic information on HPV infection among women with cytological abnormalities is essential to inform the strategy of HPV-based screening programme. The study also explored the presence of cutaneous HPV types (Beta-ß and Gamma-γ) in cervical infections. Methods: A cross-sectional study on Chinese women aged ≥25 years who were referred to public specialist out-patient clinics for colposcopy or further management of cervical cytological abnormalities were recruited between 2015 and 2016 in Hong Kong. HPV was detected and typified by the novel PCR-based Next-Generation Sequencing (NGS) strategies. Results: The overall HPV infection rate was 74% and detected in 222 of the 300 respondents, with the prevalence of cutaneous HPV infection being 2.3%. The overall prevalence of HPV infection among women with current cytological abnormalities was 79.1% (197/249). The age-specific prevalence of HPV (any-type HPV infection) among women with cytological abnormalities reached the first peak with 87.9% in the age group of 35-39 years and gradually declined to 56.0% at 55-59 years. While a second peak occurred at 65 years or above (92.9%). HPV58 (13.7%), HPV52 (11.7%), HPV53 (11.2%), HPV16 (10.0%), HPV18 (5.2%), and HPV51 (5.2%) were the top five high-risk HPV genotypes among women with cytological abnormalities. Any-HPV type infection was significantly associated with an abnormal cervical smear (OR = 3.7; 95% CI 2.0-7.1), and high-risk HPV infection was also significantly associated with an abnormal cervical smear (OR = 6.3; 95% CI 3.0-13.5). Conclusion: New evidence on the second peak of HPV infection at ≥65 years old suggests the necessity to review the current guideline for the cervical screening program extending to age 65 and above. Moreover, the high prevalence of two HPV genotypes-high-risk HPV51 and potential high-risk HPV53, among women with cytological abnormalities-suggests further research work is needed to confirm the contributory role of HPV51 and HPV53 in cervical cancer and the need for inclusion in the next generation of the HPV vaccine.

Preference of Older Adults for Flexibility in Service and Providers in Community-Based Social Care: A Discrete Choice Experiment.

Empowerment of control and choice of the service users in health and social care has been incorporated into service provision in various countries. This study aimed to elicit the preference of community-based long-term care (LTC) service users on levels of flexibility in service provision. A discrete choice experiment was performed among older community care service users to measure their preference for attributes of LTC services identified from a prior qualitative study. Each participant was asked to make choices in six choice tasks with two alternatives of hypothetical LTC services that were generated from the attributes. A generalized multinomial logistic model was applied to determine the relative importance and willingness to pay for the attributes. It found that the participants preferred multiple flexible providers, determining services by themselves, meeting case managers every month and social workers as sources of information on service provision. Significant preference heterogeneity was found for flexibility in providers and flexibility in services between those with and without activity of daily living impairment. The findings highlighted the preference of older adults for greater flexibility in LTC, while they rely heavily on social workers in decision making. The enhancement of flexibility in LTC should be supported by policies that allow the older service users to make decisions based on their own preferences or communication with social workers instead of determining the services and providers for them. Options should be offered to users to decide their preferred level of flexibility to better reflect their divided preferences.

Stage-Specific Generation of Human Pluripotent Stem Cell Derived Lung Models to Measure CFTR Function.

Human embryonic stem cells (ES) and induced pluripotent stem cells (iPSC) are powerful tools that have the potential to generate in vitro human lung epithelial cells. However, challenges in efficiency and reproducibility remain in utilizing the cells for therapy discovery platforms. Here, we optimize our previously published protocols to efficiently generate three developmental stages of the lung model (fetal lung epithelial progenitors, fLEP; immature airway epithelial spheroid, AES; air-liquid interface culture, ALI), and demonstrate its potential for cystic fibrosis (CF) drug discovery platforms. The stepwise approach directs differentiation from hPSC to definitive endoderm, anterior ventral foregut endoderm, and fetal lung progenitor cells. The article also describes the generation of immature airway epithelial spheroids in Matrigel with epithelial cells sorted by a magnetic-activated cell sorting system, and the generation of adult-like airway epithelia through air-liquid interface conditions. We demonstrate that this optimized procedure generates remarkably higher cystic fibrosis transmembrane conductance regulator (CFTR) expression and function than our previous method, and thus is uniquely suitable for CF research applications. © 2022 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: hESC/hiPSC differentiation to fetal lung progenitors Basic Protocol 2: Formation of airway epithelial spheroids Alternate Protocol 1: Cryopreservation of airway epithelial spheroids Basic Protocol 3: Differentiation and maturation in air-liquid interface culture Alternate Protocol 2: Differentiation and maturation of epithelial progenitors from airway epithelial spheroids in ALI culture.

Side press-and-release technique in endothelium-in descemet membrane endothelial keratoplasty(DMEK): A novel technique.

PURPOSE: To describe a novel technique in unfolding an endothelium-in Descemet membrane (DM) graft. METHODS: New surgical technique description. RESULTS: We describe a novel technique that allows immediate and controlled unfolding of the endothelium-in Descemet membrane graft that was successful in 5 of our DMEK patients. It is essential to acquire this "side press-and-release" technique when the graft does not unfold spontaneously as expected. CONCLUSIONS: This controlled and simple manoeuvre is an efficient and safe method of unfolding an endothelium-in DM graft.

Use of Computer Simulation in Dental Training with Special Reference to Simodont.

Simulation-based dental education has been increasingly implemented in dental training. Virtual reality simulators are being explored as an adjunct to dental education. Simulation-based dental education could serve as a powerful aid to preclinical instruction. This article provides an overview of how dental simulators can be used in dental instruction and manual dexterity training, utilizing the Simodont dental trainer as a reference. The Simodont dental trainer provides a platform for students to hone their manual dexterity skills and practice repeatedly prior to conventional clinical simulations. Additionally, it can reduce resource wastage. However, the financial cost of setting up and maintaining the system can be high. The high cost would ultimately limit the number of devices each individual school could afford, as a potential drawback to meeting the training needs of many dental students at one time. The machine's force-feedback mechanism provides trainees with the tactile experience of drilling into various tissues. Students are empowered via self-learning and assessment, with guidance provided for diagnosis and treatment. From training students on basic operative skills to providing basic aptitude tests for entrance examinations, the Simodont dental trainer's functions and potential for further development may make it a valuable tool in the field of simulation-based dental education.

Nonrestorative Management of Dental Caries.

The World Dental Federation (FDI) policy statement in 2016 advocated evidence-based caries-control measures for managing dental caries. The caries management philosophy has shifted from the traditional surgical manners to minimal intervention dentistry. Minimal intervention dentistry aims to extend the longevity of natural teeth. It places the nonrestorative approaches as a priority. The nonrestorative approaches for caries management aim to tackle the etiological factors of dental caries. Caries can be prevented or reversed by restricting the sugar intake and its frequency in the diet, improving oral hygiene practices, and using fluoride toothpaste. This article aims to present strategies for the nonrestorative management of dental caries, which are divided into four components to address the different etiological factors of dental caries. The first component is controlling dental plaque. Strategies for plaque control include oral hygiene instruction, motivational interviewing, mechanical plaque control, and chemical plaque control. The second component for nonrestorative management is reducing the risk of caries by identifying caries risk factors and protective factors, assessing personal caries risk, and customizing a treatment plan. Evidence-based measures for caries prevention include using fluoride, and dental sealants should be provided. The third component includes topical treatment to remineralise early carious lesions. The last component is long-term follow-up. Appropriate strategy adoption for the nonrestorative management of dental caries prolongs the life span of the teeth and sustains the good oral health of patients.

A new platform for high-throughput therapy testing on iPSC-derived lung progenitor cells from cystic fibrosis patients.

For those people with cystic fibrosis carrying rare CFTR mutations not responding to currently available therapies, there is an unmet need for relevant tissue models for therapy development. Here, we describe a new testing platform that employs patient-specific induced pluripotent stem cells (iPSCs) differentiated to lung progenitor cells that can be studied using a dynamic, high-throughput fluorescence-based assay of CFTR channel activity. Our proof-of-concept studies support the potential use of this platform, together with a Canadian bioresource that contains iPSC lines and matched nasal cultures from people with rare mutations, to advance patient-oriented therapy development. Interventions identified in the high-throughput, stem cell-based model and validated in primary nasal cultures from the same person have the potential to be advanced as therapies.