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1.
Cell ; 187(19): 5357-5375.e24, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39260374

RESUMEN

Genetic medicines show promise for treating various diseases, yet clinical success has been limited by tolerability, scalability, and immunogenicity issues of current delivery platforms. To overcome these, we developed a proteolipid vehicle (PLV) by combining features from viral and non-viral approaches. PLVs incorporate fusion-associated small transmembrane (FAST) proteins isolated from fusogenic orthoreoviruses into a well-tolerated lipid formulation, using scalable microfluidic mixing. Screening a FAST protein library, we identified a chimeric FAST protein with enhanced membrane fusion activity that improved gene expression from an optimized lipid formulation. Systemically administered FAST-PLVs showed broad biodistribution and effective mRNA and DNA delivery in mouse and non-human primate models. FAST-PLVs show low immunogenicity and maintain activity upon repeat dosing. Systemic administration of follistatin DNA gene therapy with FAST-PLVs raised circulating follistatin levels and significantly increased muscle mass and grip strength. These results demonstrate the promising potential of FAST-PLVs for redosable gene therapies and genetic medicines.


Asunto(s)
ADN , Proteolípidos , Animales , Ratones , ADN/metabolismo , ADN/administración & dosificación , Proteolípidos/metabolismo , Terapia Genética/métodos , Humanos , Folistatina/metabolismo , Folistatina/genética , Técnicas de Transferencia de Gen , ARN/metabolismo , ARN/administración & dosificación , Femenino , Ratones Endogámicos C57BL
2.
Exp Dermatol ; 33(6): e15097, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38840370

RESUMEN

Surgical management of basal cell carcinoma (BCC) typically involves surgical excision with post-operative margin assessment using the bread-loafing technique; or gold-standard Mohs micrographic surgery (MMS), where margins are iteratively examined for residual cancer after tumour removal, with additional excisions performed upon detecting residual tumour at margins. There is limited sampling of resection margins with bread loafing, with detection of positive margins 44% of the time using 2 mm intervals. To resolve this, we have developed three-dimensional (3D) Tissue Imaging for: (1) complete examination of cancer margins and (2) detection of tumour proximity to nerves and blood vessels. 3D Tissue optical clearing with a light sheet imaging protocol was developed for margin assessment in two datasets assessed by two independent evaluators: (1) 48 samples from 29 patients with varied BCC subtypes, sizes and pigmentation levels; (2) 32 samples with matching Mohs' surgeon reading of tumour margins using two-dimensional haematoxylin & eosin-stained sections. The 3D Tissue Imaging protocol permits a complete examination of deeper and peripheral margins. Two independent evaluators achieved negative predictive values of 92.3% and 88.24% with 3D Tissue Imaging. Images obtained from 3D Tissue Imaging recapitulates histological features of BCC, such as nuclear crowding, palisading and retraction clefting and provides a 3D context for recognising normal skin adnexal structures. Concurrent immunofluorescence labelling of nerves and blood vessels allows visualisation of structures closer to tumour-positive regions, which may have a higher risk for neural and vascular infiltration. Together, this method provides more information in a 3D spatial context, enabling better cancer management by clinicians.


Asunto(s)
Carcinoma Basocelular , Imagenología Tridimensional , Márgenes de Escisión , Cirugía de Mohs , Neoplasias Cutáneas , Humanos , Carcinoma Basocelular/diagnóstico por imagen , Carcinoma Basocelular/cirugía , Carcinoma Basocelular/patología , Neoplasias Cutáneas/diagnóstico por imagen , Neoplasias Cutáneas/cirugía , Neoplasias Cutáneas/patología
4.
Front Psychol ; 14: 1085208, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36891206

RESUMEN

In a public health crisis, communication plays a vital role in making sure policies and recommendations from the government level get disseminated accurately to its people and is only considered as effective when the public accepts, supports, complies to, and engages in policies or behaves as per governments' recommendations. Adopting the multivariate audience segmentation strategy for health communication, this study uses a data-driven analytical method to (1) identify audience segments of public health crisis communication in Singapore based on knowledge, risk perception, emotional responses, and preventive behaviors; and (2) characterize each audience segment according to demographic factors, personality traits, information processing styles, and health information preferences. Results (N = 2033) from a web-based questionnaire executed in August 2021 have identified three audience segments: the less-concerned (n = 650), the risk-anxious (n = 142), and the risk-majority (n = 1,241). This study offers insights to how audiences of public health crisis communication perceive, process, and respond to information directed to them during the pandemic, thereby informing policy makers to tailor more targeted public health communication interventions in promoting positive attitude and behavior change.

5.
Methods Mol Biol ; 2579: 87-97, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36045200

RESUMEN

The typical cell cycle in eukaryotes is composed of four phases including the G1, S, G2, and M phases. G1, S, and G2 together are called interphase. Cell synchronization is a process that brings cultured cells at different stages of the cell cycle to the same phase, which allows the study of phase-specific cellular events. While interphase cells can be easily distinguished from mitotic cells by examining their chromosome morphology, it is much more difficult to separate and distinguish the interphases from each other. Here, we describe drug-derived protocols for synchronizing HeLa cells to various interphases of the cell cycle: G1 phase, S phase, and G2 phase. G1 phase synchronization is achieved through serum starvation, S phase synchronization is achieved through a double thymidine block, and G2 phase synchronization is achieved through the release of the double thymidine block followed by roscovitine treatment. Successful synchronization can be assessed using flow cytometry to examine the DNA content and Western blot to examine the expression of various cyclins.


Asunto(s)
Fase G2 , Mitosis , Ciclo Celular/genética , Citometría de Flujo/métodos , Células HeLa , Humanos , Interfase , Timidina/metabolismo
6.
Methods Mol Biol ; 2579: 99-110, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36045201

RESUMEN

The cell cycle is a series of events leading to cell replication. When plated at low cell densities in serum-containing medium, cultured cells start to proliferate, moving through the four phases of the cell cycle: G1, S, G2, and M. Mitosis is the most dynamic period of the cell cycle, involving a major reorganization of virtually all cell components. Mitosis is further divided into prophase, prometaphase, metaphase, anaphase, and telophase, which can be easily distinguished from one another by protein markers and/or comparing their chromosome morphology under fluorescence microscope. The progression of the cell cycle through these mitotic subphases is tightly regulated by complicated molecular mechanisms. Synchronization of cells to the mitotic subphases is important for understanding these molecular mechanisms. Here, we describe a protocol to synchronize Hela cells to prometaphase, metaphase, and anaphase/telophase. In this protocol, Hela cells are first synchronized to the early S phase by a double thymidine block. Following the release of the block, the cells are treated with nocodazole, MG132, and blebbistatin to arrest them at prometaphase, metaphase, and anaphase/telophase, respectively. Successful synchronization is assessed using Western blot and fluorescence microscopy.


Asunto(s)
Anafase , Mitosis , Células HeLa , Humanos , Metafase , Telofase
8.
Ann Acad Med Singap ; 50(6): 456-466, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34195752

RESUMEN

INTRODUCTION: Melanomas in Asians have different clinicopathological characteristics and prognosis from melanomas in Caucasians. This study reviewed the epidemiology and treatment outcomes of cutaneous melanoma diagnosed at a tertiary referral dermatology centre in Singapore, which has a multiracial population. The study also determined whether Asians had comparable relapse-free and overall survival periods to Caucasians in Singapore. METHOD: This is a retrospective review of cutaneous melanoma cases in our centre between 1996 and 2015. RESULTS: Sixty-two cases of melanoma were diagnosed in 61 patients: 72.6% occurred in Chinese, 19.4% in Caucasians and 3.2% in Indians, with an over-representation of Caucasians. Superficial spreading melanoma, acral lentiginous melanoma and nodular melanoma comprised 37.1%, 35.5% and 22.6% of the cases, respectively. The median time interval to diagnosis was longer in Asians than Caucasians; median Breslow's thickness in Asians were significantly thicker than in Caucasians (2.6mm versus 0.9mm, P=0.018) and Asians tend to present at a later stage. The mortality rates for Asians and Caucasians were 52% and 0%, respectively. CONCLUSION: More physician and patient education on skin cancer awareness is needed in our Asian-predominant population for better outcomes.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Humanos , Melanoma/epidemiología , Melanoma/terapia , Pronóstico , Estudios Retrospectivos , Singapur/epidemiología , Neoplasias Cutáneas/epidemiología , Neoplasias Cutáneas/terapia , Resultado del Tratamiento
11.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-887513

RESUMEN

INTRODUCTION@#Melanomas in Asians have different clinicopathological characteristics and prognosis from melanomas in Caucasians. This study reviewed the epidemiology and treatment outcomes of cutaneous melanoma diagnosed at a tertiary referral dermatology centre in Singapore, which has a multiracial population. The study also determined whether Asians had comparable relapse-free and overall survival periods to Caucasians in Singapore.@*METHOD@#This is a retrospective review of cutaneous melanoma cases in our centre between 1996 and 2015.@*RESULTS@#Sixty-two cases of melanoma were diagnosed in 61 patients: 72.6% occurred in Chinese, 19.4% in Caucasians and 3.2% in Indians, with an over-representation of Caucasians. Superficial spreading melanoma, acral lentiginous melanoma and nodular melanoma comprised 37.1%, 35.5% and 22.6% of the cases, respectively. The median time interval to diagnosis was longer in Asians than Caucasians; median Breslow's thickness in Asians were significantly thicker than in Caucasians (2.6mm versus 0.9mm, @*CONCLUSION@#More physician and patient education on skin cancer awareness is needed in our Asian-predominant population for better outcomes.


Asunto(s)
Humanos , Melanoma/terapia , Pronóstico , Estudios Retrospectivos , Singapur/epidemiología , Neoplasias Cutáneas/terapia , Resultado del Tratamiento
12.
Ann Acad Med Singap ; 49(10): 749-755, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33283838

RESUMEN

INTRODUCTION: The human papillomavirus (HPV) vaccine has been reported to lead to clinical clearance of lesions when used as an off-label treatment for recalcitrant extragenital warts. The aim of the study is to evaluate the therapeutic and adverse effects of HPV vaccine as an adjunctive therapy for treatment-resistant acral warts. METHODS: Patients with persistent warts despite first and second line therapies, and subsequently receiving the quadrivalent HPV vaccine between July 2013 and June 2016 as an adjunctive treatment for recalcitrant warts at the National Skin Centre, were included. RESULTS: Twenty-six patients with a median age of 34 years (range 8 to 77 years) were treated with the HPV vaccine. Nineteen (73.1%) patients completed 3 doses of the vaccine, of whom 5 (26%) achieved complete clearance, 8 (42%) had partial clearance and 6 (32%) did not respond to the vaccine. Among the 4 patients who received 2 doses of the vaccine, 3 (75%) had complete clearance whereas 1 (25%) had partial improvement of their warts. None of the patients reported adverse reactions. CONCLUSION: Our study suggests a potential adjunctive role of the HPV vaccine in the treatment of acral warts recalcitrant to conventional therapy.


Asunto(s)
Vacunas contra Papillomavirus , Verrugas , Adolescente , Adulto , Anciano , Niño , Terapia Combinada , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Verrugas/terapia , Adulto Joven
13.
Br J Radiol ; 93(1114): 20200565, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32783630

RESUMEN

OBJECTIVES: To investigate via computer simulation, an optimised tube voltage (kVp) range for caesium iodide (CsI)-based digital radiography (DR) of the abdomen, pelvis and lumbar spine. METHODS: Software capable of simulating abdomen, pelvis and spine radiographs was used. Five evaluators graded clinical image criteria in images of 20 patients at tube voltages ranging from 60 to 120 kVp in 10 kVp increments. These criteria were scored blindly against the same patient reconstructed at a specific reference kVp. Linear mixed effects analysis was used to evaluate image scores for each criterion and test for statistical significance. RESULTS: Score was dependent on tube voltage and image criteria; both were statistically significant. All criteria for all anatomies scored very poorly at 60 kVp. Scores for abdomen, pelvis and spine imaging peaked at 70, 70 and 100 kVp, respectively, but other kVp values were not significantly poorer. CONCLUSIONS: Results indicate optimum tube voltages of 70 kVp for abdomen and pelvis (with an optimum range 70-120 kVp), and 100 kVp (optimum range 80-120 kVp) for lumbar spine. ADVANCES IN KNOWLEDGE: There are no recommendations for optimised tube voltage parameters for DR abdomen, pelvis or lumbar spine imaging. This study has investigated and recommended an optimal tube voltage range.


Asunto(s)
Abdomen/diagnóstico por imagen , Pelvis/diagnóstico por imagen , Intensificación de Imagen Radiográfica/métodos , Columna Vertebral/diagnóstico por imagen , Algoritmos , Cesio , Simulación por Computador , Humanos , Yoduros , Fantasmas de Imagen , Interpretación de Imagen Radiográfica Asistida por Computador , Programas Informáticos
14.
J Clin Aesthet Dermatol ; 13(3): 31-36, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32308795

RESUMEN

BACKGROUND: Two extracts derived from the gastropod Cryptomphalus aspersa have been shown to have dermal regeneration properties: SCA® (secretion filtrate) with fibroblast growth factor-like activity and IFC®-CAF (cellular activating factor), a snail egg extract with skin stem cell activation activity. OBJECTIVE: The objectives of this study were to evaluate the synergic antiaging activity and tolerability of SCA and IFC-CAF in a combined regimen compared to vehicle as a placebo control. METHODS: A three-month, single-center, double-blinded, randomized, vehicle-controlled trial assessed the effects of a daily skincare routine divided into two treatment phases, as follows: intensive (1 month) and maintenance (2 months). Fifty women, aged 45-65 years, with signs of photoaging were randomized to receive either the active ingredients (n=30) or vehicle (n=20). Clinical evaluations included objective measurements of barrier function and skin hydration, elasticity, and color/brightness. Subjective assessments were conducted according to the Rao-Goldman and Glogau scales for wrinkles, the Patient Global Assessment (PGA) scale and Investigator Global Assessment (IGA) scale. RESULTS: Subjects in the active treatment group experienced reductions in transepidermal water loss and significant improvements in skin roughness, firmness, and elasticity. Both groups showed significant improvements in fine lines and wrinkles. PGA and IGA assessments indicated greater improvement in the active treatment group. CONCLUSION: The active snail extract treatment appears to be effective in improving signs of skin aging in women 45 to 65 years old. Larger randomized, controlled studies are needed to confirm our results.

15.
EBioMedicine ; 39: 44-58, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30528453

RESUMEN

BACKGROUND: Immune adaptation with aging is a major of health outcomes. Studies in humans have mainly focus on αß T cells while γδ T cells have been neglected despite their role in immunosurveillance. We investigated the impact of aging on γδ T cell subsets phenotypes, functions, senescence and their molecular response to stress. METHODS: Peripheral blood of young and old donors in Singapore have been used to assess the phenotype, functional capacity, proliferation capacity and gene expression of the various γδ T cell subsets. Peripheral blood mononuclear cells from apheresis cones and young donors have been used to characterize the telomere length, epigenetics profile and DNA damage response of the various γδ T cell subsets phenotype. FINDINGS: Our data shows that peripheral Vδ2+ phenotype, functional capacity (cytokines, cytotoxicity, proliferation) and gene expression profile are specific when compared against all other αß and γδ T cells in aging. Hallmarks of senescence including telomere length, epigenetic profile and DNA damage response of Vδ2+ also differs against all other αß and γδ T cells. INTERPRETATION: Our results highlight the differential impact of lifelong stress on γδ T cells subsets, and highlight possible mechanisms that enable Vδ2+ to be resistant to cellular aging. The new findings reinforce the concept that Vδ2+ have an "innate-like" behavior and are more resilient to the environment as compared to "adaptive-like" Vδ1+ T cells.


Asunto(s)
Envejecimiento/genética , Citocinas/genética , Receptores de Antígenos de Linfocitos T gamma-delta/genética , Subgrupos de Linfocitos T/citología , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/inmunología , Proliferación Celular , Senescencia Celular , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Singapur , Subgrupos de Linfocitos T/inmunología , Acortamiento del Telómero , Adulto Joven
18.
Cells ; 7(12)2018 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-30544639

RESUMEN

The overactivation of epidermal growth factor (EGF) receptor (EGFR) is implicated in various cancers. Endocytosis plays an important role in EGFR-mediated cell signaling. We previously found that EGFR endocytosis during mitosis is mediated differently from interphase. While the regulation of EGFR endocytosis in interphase is well understood, little is known regarding the regulation of EGFR endocytosis during mitosis. Here, we found that contrary to interphase cells, mitotic EGFR endocytosis is more reliant on the activation of the E3 ligase CBL. By transfecting HeLa, MCF-7, and 293T cells with CBL siRNA or dominant-negative 70z-CBL, we found that at high EGF doses, CBL is required for EGFR endocytosis in mitotic cells, but not in interphase cells. In addition, the endocytosis of mutant EGFR Y1045F-YFP (mutation at the direct CBL binding site) is strongly delayed. The endocytosis of truncated EGFR Δ1044-YFP that does not bind to CBL is completely inhibited in mitosis. Moreover, EGF induces stronger ubiquitination of mitotic EGFR than interphase EGFR, and mitotic EGFR is trafficked to lysosomes for degradation. Furthermore, we showed that, different from interphase, low doses of EGF still stimulate EGFR endocytosis by non-clathrin mediated endocytosis (NCE) in mitosis. Contrary to interphase, CBL and the CBL-binding regions of EGFR are required for mitotic EGFR endocytosis at low doses. This is due to the mitotic ubiquitination of the EGFR even at low EGF doses. We conclude that mitotic EGFR endocytosis exclusively proceeds through CBL-mediated NCE.

20.
J Cell Biochem ; 119(1): 237-239, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28467644

RESUMEN

In the current study, we analyzed ten gene expression data sets including RNA-sequencing and microarray experiment data during the direct reprogramming of mouse and human fibroblasts to induced neurons and found common gene expression pattern across all data sets for this conversion.


Asunto(s)
Técnicas de Reprogramación Celular , Reprogramación Celular , Fibroblastos/metabolismo , Regulación de la Expresión Génica , Neuronas/metabolismo , Animales , Humanos , Ratones
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