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1.
J Biomed Sci ; 31(1): 47, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38724973

RESUMEN

The field of regenerative medicine has witnessed remarkable advancements with the emergence of induced pluripotent stem cells (iPSCs) derived from a variety of sources. Among these, urine-derived induced pluripotent stem cells (u-iPSCs) have garnered substantial attention due to their non-invasive and patient-friendly acquisition method. This review manuscript delves into the potential and application of u-iPSCs in advancing precision medicine, particularly in the realms of drug testing, disease modeling, and cell therapy. U-iPSCs are generated through the reprogramming of somatic cells found in urine samples, offering a unique and renewable source of patient-specific pluripotent cells. Their utility in drug testing has revolutionized the pharmaceutical industry by providing personalized platforms for drug screening, toxicity assessment, and efficacy evaluation. The availability of u-iPSCs with diverse genetic backgrounds facilitates the development of tailored therapeutic approaches, minimizing adverse effects and optimizing treatment outcomes. Furthermore, u-iPSCs have demonstrated remarkable efficacy in disease modeling, allowing researchers to recapitulate patient-specific pathologies in vitro. This not only enhances our understanding of disease mechanisms but also serves as a valuable tool for drug discovery and development. In addition, u-iPSC-based disease models offer a platform for studying rare and genetically complex diseases, often underserved by traditional research methods. The versatility of u-iPSCs extends to cell therapy applications, where they hold immense promise for regenerative medicine. Their potential to differentiate into various cell types, including neurons, cardiomyocytes, and hepatocytes, enables the development of patient-specific cell replacement therapies. This personalized approach can revolutionize the treatment of degenerative diseases, organ failure, and tissue damage by minimizing immune rejection and optimizing therapeutic outcomes. However, several challenges and considerations, such as standardization of reprogramming protocols, genomic stability, and scalability, must be addressed to fully exploit u-iPSCs' potential in precision medicine. In conclusion, this review underscores the transformative impact of u-iPSCs on advancing precision medicine and highlights the future prospects and challenges in harnessing this innovative technology for improved healthcare outcomes.


Asunto(s)
Tratamiento Basado en Trasplante de Células y Tejidos , Células Madre Pluripotentes Inducidas , Medicina de Precisión , Humanos , Medicina de Precisión/métodos , Células Madre Pluripotentes Inducidas/citología , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Evaluación Preclínica de Medicamentos/métodos , Orina/citología , Medicina Regenerativa/métodos
2.
Int J Mol Sci ; 25(7)2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38612560

RESUMEN

Retinal degenerative diseases, including age-related macular degeneration and retinitis pigmentosa, significantly contribute to adult blindness. The Royal College of Surgeons (RCS) rat is a well-established disease model for studying these dystrophies; however, molecular investigations remain limited. We conducted a comprehensive analysis of retinal degeneration in RCS rats, including an immunodeficient RCS (iRCS) sub-strain, using ocular coherence tomography, electroretinography, histology, and molecular dissection using transcriptomics and immunofluorescence. No significant differences in retinal degeneration progression were observed between the iRCS and immunocompetent RCS rats, suggesting a minimal role of adaptive immune responses in disease. Transcriptomic alterations were primarily in inflammatory signaling pathways, characterized by the strong upregulation of Tnfa, an inflammatory signaling molecule, and Nox1, a contributor to reactive oxygen species (ROS) generation. Additionally, a notable decrease in Alox15 expression was observed, pointing to a possible reduction in anti-inflammatory and pro-resolving lipid mediators. These findings were corroborated by immunostaining, which demonstrated increased photoreceptor lipid peroxidation (4HNE) and photoreceptor citrullination (CitH3) during retinal degeneration. Our work enhances the understanding of molecular changes associated with retinal degeneration in RCS rats and offers potential therapeutic targets within inflammatory and oxidative stress pathways for confirmatory research and development.


Asunto(s)
Degeneración Macular , Degeneración Retiniana , Retinitis Pigmentosa , Cirujanos , Humanos , Adulto , Animales , Ratas , Retina
3.
Front Oral Health ; 5: 1332980, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38433948

RESUMEN

Background: Periodontitis is initiated by a dysbiotic activity and furthermore leads to a chronic inflammatory response. The presence of pro-inflammatory markers plays an important role in the inflammatory load. Macrophage inflammatory protein-1 alpha (MIP-1α) and C-reactive protein (CRP) are pro- inflammatory biomarkers that quantify clinical and subclinical inflammation in cardiac ischemia in cardiac inflammation and disease. Adiponectin is an anti-inflammatory marker associated with good health. The susceptibility of periodontitis patients to cardiovascular events needs to be evaluated. Objective: This study aims to assess the levels of biomarkers in periodontitis patients with and without acute myocardial infarction (AMI) compared to controls. Material and methods: Pro-inflammatory and anti-inflammatory analytes were examined by collecting unstimulated saliva from three groups (n = 20/each): healthy individuals, individuals with stage III periodontitis, and post-myocardial infarction patients with stage III periodontitis. The samples were collected within 48 h of AMI. Results: Adiponectin levels were significantly lower in patients with periodontitis with and without AMI compared to controls, while CRP and MIP-1α were significantly higher in patients with periodontitis with and without AMI compared to controls. The highest titers for MIP-1α and CRP were detected among patients with periodontitis with and AMI. Conclusion: Our study provides possible evidence of the association between periodontitis and salivary analytes that occur in tandem with cardiovascular disease. The lower levels of Adiponectin and higher levels of CRP and MIP-1α in patients with periodontitis indicate that this condition is a potential risk factor for cardiovascular disease. The findings emphasize the importance of early detection and intervention for periodontitis patients to prevent cardiovascular events.

4.
Singapore Med J ; 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38363652

RESUMEN

ABSTRACT: Asthma is a major chronic disease affecting children, and children with difficult-to-treat asthma account for a disproportionate share of resource utilisation and healthcare costs. This review presents a comprehensive and up-to-date overview of the treatment strategies in difficult-to-treat paediatric asthma. Mimickers of asthma must first be ruled out, and the diagnosis confirmed with objective tests whenever possible. The effect of comorbid conditions such as obesity, smoking, other atopic conditions and psychosocial factors on asthma control and severity should be considered. Treatment can then be optimised by implementing personalised strategies, including the use of appropriate drug delivery devices and adherence monitoring. Biologics can be an alternative treatment option for selected patients but should not be a substitute for addressing poor adherence. Many patients with difficult-to-treat asthma may not have severe asthma, and the physician should work with patients and families to achieve good asthma control via an individualised approach.

5.
Bioengineering (Basel) ; 11(2)2024 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-38391660

RESUMEN

Functional ultrasound (fUS) flow imaging provides a non-invasive method for the in vivo study of cerebral blood flow and neural activity. This study used functional flow imaging to investigate rat brain's response to ultrasound and colored-light stimuli. Male Long-Evan rats were exposed to direct full-field strobe flashes light and ultrasound stimulation to their retinas, while brain activity was measured using high-frequency ultrasound imaging. Our study found that light stimuli, particularly blue light, elicited strong responses in the visual cortex and lateral geniculate nucleus (LGN), as evidenced by changes in cerebral blood volume (CBV). In contrast, ultrasound stimulation elicited responses undetectable with fUS flow imaging, although these were observable when directly measuring the brain's electrical signals. These findings suggest that fUS flow imaging can effectively differentiate neural responses to visual stimuli, with potential applications in understanding visual processing and developing new diagnostic tools.

6.
J Neurosci Methods ; 405: 110095, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38403001

RESUMEN

BACKGROUND: The retinotopic map property of the superior colliculus (SC) is a reliable indicator of visual functional changes in rodents. Electrophysiological mapping of the SC using a single electrode has been employed for measuring visual function in rat and mouse disease models. Single electrode mapping is highly laborious requiring long-term exposure to the SC surface and prolonged anesthetic conditions that can adversely affect the mapping data. NEW METHOD: To avoid the above-mentioned issues, we fabricated a fifty-six (56) electrode multi-electrode array (MEA) for rapid and reliable visual functional mapping of the SC. Since SC is a dome-shaped structure, the array was made of electrodes with dissimilar tip lengths to enable simultaneous and uniform penetration of the SC. RESULTS: SC mapping using the new MEA was conducted in retinal degenerate (RD) Royal College of Surgeons (RCS) rats and rats with focal retinal damage induced by green diode laser. For SC mapping, the MEA was advanced into the SC surface and the visual activities were recorded during full-filed light stimulation of the eye. Based on the morphological examination, the MEA electrodes covered most of the exposed SC area and penetrated the SC surface at a relatively uniform depth. MEA mapping in RCS rats (n=9) demonstrated progressive development of a scotoma in the SC that corresponded to the degree of photoreceptor loss. MEA mapping in the laser damaged rats demonstrated the presence of a scotoma in the SC area that corresponded to the location of retinal laser injury. COMPARISON WITH EXISTING METHODS AND CONCLUSIONS: The use of MEA for SC mapping is advantageous over single electrode recording by enabling faster recordings and reducing anesthesia time. This study establishes the feasibility of the MEA technique for rapid and efficient SC mapping, particularly advantageous for evaluating therapeutic effects in retinal degenerate rat disease models.


Asunto(s)
Escotoma , Colículos Superiores , Humanos , Ratas , Animales , Ratones , Colículos Superiores/fisiología , Retina/fisiología , Luz , Electrodos
7.
Exp Eye Res ; 240: 109789, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38242423

RESUMEN

Age-related macular degeneration (AMD), a leading cause of vision loss, primarily arises from the degeneration of retinal pigment epithelium (RPE) and photoreceptors. Current therapeutic options for dry AMD are limited. Encouragingly, cultured RPE cells on parylene-based biomimetic Bruch's membrane demonstrate characteristics akin to the native RPE layer. In this study, we cultivated human embryonic stem cell-derived polarized RPE (hESC-PRPE) cells on parylene membranes at both small- and large-scale settings, collecting conditioned supernatant, denoted as PRPE-SF. We conducted a comprehensive analysis of the morphology of the cultured hESC-RPE cells and the secreted growth factors in PRPE-SF. To evaluate the in vivo efficacy of these products, the product was administered via intravitreal injections of PRPE-SF in immunodeficient Royal College of Surgeons (iRCS) rats, a model for retinal degeneration. Our study not only demonstrated the scalability of PRPE-SF production while maintaining RPE cell phenotype but also showed consistent protein concentrations between small- and large-scale batches. We consistently identified 10 key factors in PRPE-SF, including BMP-7, IGFBP-2, IGFBP-3, IGFBP-4, IGFBP-6, MANF, PEDF, PDGF-AA, TGFß1, and VEGF. Following intravitreal administration of PRPE-SF, we observed a significant increase in the thickness of the outer nuclear layer (ONL) and photoreceptor preservation in iRCS rats. Furthermore, correlation analysis revealed that IGFBP-3, IGFBP-4, MANF, PEDF, and TGFß1 displayed positive associations with in vivo bioactivity, while GDF-15 exhibited a negative correlation. Overall, this study highlights the feasibility of scaling up PRPE-SF production on parylene membranes without compromising its essential constituents. The outcomes of PRPE-SF administration in an animal model of retinal degeneration present substantial potential for photoreceptor preservation. Moreover, the identification of candidate surrogate potency markers, showing strong positive associations with in vivo bioactivity, lays a solid foundation for the development of a promising therapeutic intervention for retinal degenerative diseases.


Asunto(s)
Polímeros , Degeneración Retiniana , Epitelio Pigmentado de la Retina , Xilenos , Humanos , Animales , Ratas , Epitelio Pigmentado de la Retina/metabolismo , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/metabolismo , Proteína 4 de Unión a Factor de Crecimiento Similar a la Insulina , Degeneración Retiniana/metabolismo
9.
Artículo en Inglés | MEDLINE | ID: mdl-37792653

RESUMEN

An ultrasound concave 2-D ring array transducer was designed for applications in visual stimulation of the retina with a long-term goal to restore vision in individuals with intact neurons but suffering blindness due to retinopathies. The array was synthesized and has a frequency of 20 MHz (0.075-mm wavelengths in water), 18-mm focal length (the curvature of the concave array), 1004 elements (with a pitch of 4.0 wavelengths), and inner and outer diameters of 9 and 14 mm, respectively. Wave patterns produced with the array at the focal distance were simulated. Results show that the wave patterns obtained can achieve a full-width-at-half-maximum (FWHM) resolution of 0.147 mm that is very close to the FWHM diffraction limit (0.136 mm). In addition, a scaled experiment at a lower frequency of 2.5 MHz was performed. The result is very close to those obtained with the simulations.


Asunto(s)
Retina , Transductores , Humanos , Diseño de Equipo , Ultrasonografía/métodos , Fantasmas de Imagen , Retina/diagnóstico por imagen
10.
Sci Rep ; 13(1): 15924, 2023 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-37741821

RESUMEN

Retinal diseases such as retinitis pigmentosa (RP) and age-related macular degeneration (AMD) are characterized by unrelenting neuronal death. However, electrical stimulation has been shown to induce neuroprotective changes in the retina capable of slowing down the progression of retinal blindness. In this work, a multi-scale computational model and modeling platform were used to design electrical stimulation strategies to better target the bipolar cells (BCs), that along with photoreceptors are affected at the early stage of retinal degenerative diseases. Our computational findings revealed that biphasic stimulus pulses of long pulse duration could decrease the activation threshold of BCs, and the differential stimulus threshold between ganglion cells (RGCs) and BCs, offering the potential of targeting the BCs during the early phase of degeneration. In vivo experiments were performed to evaluate the electrode placement and parameters found to target bipolar cells and evaluate the safety and efficacy of the treatment. Results indicate that the proposed transcorneal Electrical Stimulation (TES) strategy can attenuate retinal degeneration in a Royal College of Surgeon (RCS) rodent model, offering the potential to translate this work to clinical practice.


Asunto(s)
Degeneración Macular , Degeneración Retiniana , Humanos , Animales , Degeneración Retiniana/terapia , Retina , Modelos Animales , Estimulación Eléctrica
11.
BMJ Case Rep ; 16(9)2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37696606

RESUMEN

An early adolescent boy presented with 1-week history of left-sided chest pain, localised to the anterior aspect of seventh intercostal space. A chest radiograph revealed a round opacity measuring 2.6×2.4 cm in the left mid zone. A CT scan of the chest confirmed a solitary well-circumscribed pulmonary nodule measuring 2.7×2.4 cm in the central left upper lobe, adjacent to the anterior segmental bronchus. Positron emission tomography scan showed mild to moderate fluorodeoxyglucose uptake (maximum standardized uptake value 5.2) in the nodule. He underwent a video-assisted left upper lobectomy. Histology of the nodule was consistent with sclerosing pneumocytoma, a rare benign lung neoplasm that occurs predominantly in middle-aged women of Asian descent. This case highlights the challenges in diagnosis and management of solitary pulmonary nodules in children, especially those who remain symptomatic or only have minimal symptoms and provides a pragmatic approach to this condition.


Asunto(s)
Nódulo Pulmonar Solitario , Masculino , Niño , Persona de Mediana Edad , Humanos , Adolescente , Femenino , Nódulo Pulmonar Solitario/diagnóstico por imagen , Nódulo Pulmonar Solitario/cirugía , Tórax , Transporte Biológico , Bronquios , Dolor en el Pecho
12.
Cells ; 12(13)2023 06 22.
Artículo en Inglés | MEDLINE | ID: mdl-37443724

RESUMEN

Retinal degenerative diseases, including age-related macular degeneration (AMD) and retinitis pigmentosa, lack effective therapies. Conventional monotherapeutic approaches fail to target the multiple affected pathways in retinal degeneration. However, the retinal pigment epithelium (RPE) secretes several neurotrophic factors addressing diverse cellular pathways, potentially preserving photoreceptors. This study explored human embryonic stem cell-derived, polarized RPE soluble factors (PRPE-SF) as a combination treatment for retinal degeneration. PRPE-SF promoted retinal progenitor cell survival, reduced oxidative stress in ARPE-19 cells, and demonstrated critical antioxidant and anti-inflammatory effects for preventing retinal degeneration in the Royal College of Surgeons (RCS) rat model. Importantly, PRPE-SF treatment preserved retinal structure and scotopic b-wave amplitudes, suggesting therapeutic potential for delaying retinal degeneration. PRPE-SF is uniquely produced using biomimetic membranes for RPE polarization and maturation, promoting a protective RPE secretome phenotype. Additionally, PRPE-SF is produced without animal serum to avoid immunogenicity in future clinical development. Lastly, PRPE-SF is a combination of neurotrophic factors, potentially ameliorating multiple dysfunctions in retinal degenerations. In conclusion, PRPE-SF offers a promising therapeutic candidate for retinal degenerative diseases, advancing the development of effective therapeutic strategies for these debilitating conditions.


Asunto(s)
Degeneración Retiniana , Epitelio Pigmentado de la Retina , Ratas , Humanos , Animales , Epitelio Pigmentado de la Retina/metabolismo , Degeneración Retiniana/metabolismo , Secretoma , Retina/metabolismo , Células Fotorreceptoras/metabolismo
13.
Bioengineering (Basel) ; 10(5)2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37237647

RESUMEN

The optic nerve is the second cranial nerve (CN II) that connects and transmits visual information between the retina and the brain. Severe damage to the optic nerve often leads to distorted vision, vision loss, and even blindness. Such damage can be caused by various types of degenerative diseases, such as glaucoma and traumatic optic neuropathy, and result in an impaired visual pathway. To date, researchers have not found a viable therapeutic method to restore the impaired visual pathway; however, in this paper, a newly synthesized model is proposed to bypass the damaged portion of the visual pathway and set up a direct connection between a stimulated visual input and the visual cortex (VC) using Low-frequency Ring-transducer Ultrasound Stimulation (LRUS). In this study, by utilizing and integrating various advanced ultrasonic and neurological technologies, the following advantages are achieved by the proposed LRUS model: 1. This is a non-invasive procedure that uses enhanced sound field intensity to overcome the loss of ultrasound signal due to the blockage of the skull. 2. The simulated visual signal generated by LRUS in the visual-cortex-elicited neuronal response in the visual cortex is comparable to light stimulation of the retina. The result was confirmed by a combination of real-time electrophysiology and fiber photometry. 3. VC showed a faster response rate under LRUS than light stimulation through the retina. These results suggest a potential non-invasive therapeutic method for restoring vision in optic-nerve-impaired patients using ultrasound stimulation (US).

14.
J Indian Soc Periodontol ; 27(1): 4-30, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36873963

RESUMEN

Oral health is vital for the general well-being, overall body health and the quality of life throughout our lifetime. Most of the oral diseases and conditions are largely related to the maintenance of oral hygiene, lacking that people suffer from diverse oral diseases at different times in their life. With greater life expectancy, the individuals have teeth involved with periodontal diseases that would not only require professional care but also home gum care for them to last a lifetime. Indian Society of Periodontology (ISP) has recognized the need for systematic documents to update everyday clinical practice of general dental practitioners and have provided evidence-based consensus documents, namely good clinical practice recommendations from time to time to raise the oral health-related awareness and standards of oral healthcare delivery across the country. The current set of clinical practice recommendations focused to "Gum Care for All", is aimed at emphasizing and enhancing the awareness regarding oral health promotion, maintenance, and disease prevention. Twenty-five subject matter experts from across the nation, prepared these recommendations after a thorough literature review and group discussions. The document has been prepared in three distinct sections, namely pretherapeutic, therapeutic, and post therapeutic, to provide guidance during the respective phases of patient management and may serve as a quick and concise reference to the readers. The guidelines shall provide the distinct definitions, signs and symptoms, treatment required; recall visit specifications for plausible clinical case situations, home care advice regarding maintenance of oral hygiene including information on brushing technique, care and change of brush, use of interdental aids, and mouthwashes, etc. The document should advocate and guide the combined efforts of general dentists, and the population at large toward an empowered, evidence based, integrated, and comprehensive oral health care, which shall enhance the healthful functioning and longevity of the dentition and general health of the individual.

15.
Mol Syndromol ; 14(1): 21-29, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36777711

RESUMEN

Background: Cardiofaciocutaneous syndrome (CFCS) is a rare genetic condition caused by mutations in BRAF, KRAS, MAP2K1, or MAP2K2. It is characterized by ectodermal abnormalities, cardiac defects, intellectual disability, and distinct craniofacial features. CFCS falls under a group of conditions caused by mutations in the RAS/MAPK pathway called RASopathies which share many features. In particular, CFCS has significant phenotypic overlaps with Costello syndrome (CS) and Noonan syndrome (NS). Objective: The aim of this study was to assess the patients‧ phenotypic features for syndromic disorders and evaluate the use of molecular testing to clarify the clinical diagnosis. Method: The patients were recruited for genetic testing with written informed consent. Genomic DNA from venous blood was sequenced and potential variants were identified via targeted next-generation sequencing. Their phenotypic features were compared with other CFCS cases carrying pathogenic variants in the same gene. Results and Discussion: One patient had a de novo variant (c.370C>T; p.P124S) in MAP2K1 and presented with mild and typical features which do not significantly affect her quality of life. The second patient presented with severe features, including failure to thrive, feeding difficulties, epileptic spasms, septal hypertrophy, and global developmental delay, and developed chronic lung disease and sequelae from multiple infections. She had a severe disease course and severe global developmental delay. The discovery of a de novo variant (c.371C>A; p.P124Q) in MAP2K1, which had been reported in another patient with a similar phenotype, clarifies her clinical diagnosis. Her presentations add to existing reports that support expanding the CFCS phenotype to include features previously thought to be more suggestive of CS. Conclusion: The genetic findings for the 2 patients affirm the use of identified gene mutations to confirm the clinical diagnosis of syndromic disorders and add to the phenotypic spectrum of CFCS.

16.
Singapore Med J ; 2023 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-36695280

RESUMEN

Behavioural sleep problems are very common in children and are concerns for many parents. This review discusses normal sleep physiology and sleep development and focuses on common behavioural sleep problems in childhood, including behavioural insomnia of childhood, parasomnias and sleep-related movement disorders, highlighting their clinical features and management. Behavioural insomnia of childhood is characterised by learned difficulties in falling asleep and/or staying asleep. Management includes establishing bedtime routines and behavioural techniques. Parasomnias include confusional arousals, sleepwalking, sleep terrors and nightmares, and these usually resolve with time. Management includes parental reassurance and behavioural interventions such as scheduled awakening. With regards to sleep enuresis, management includes behavioural modifications, enuresis alarm and desmopressin. Sleep-related movement disorders include sleep-related bruxism and sleep-related rhythmic movements, of which body rocking is the most common. Early identification and management of behavioural sleep problems may prevent their negative impact on children as well as their families.

17.
Singapore Med J ; 64(5): 285-293, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-34544213

RESUMEN

Healthcare delivery is moving towards a more personalised and patient-centric approach. There is now an appropriate emphasis on providing value in our healthcare system. Patient-reported outcome measures (PROMs) assess our patients' perceptions of the status of their health and quality of life, measured over a period of time. PROM is an integral component of a value-driven and value-based healthcare system and is key if we want to practise value-based medicine. In paediatrics and child health, PROMs, if implemented well with appropriate measurement tools that are regularly updated and validated in a self-learning healthcare ecosystem, will help to enhance personalised healthcare delivery and collectively improve the health of the community at large. This review covers the role of PROMs in paediatrics, as well as their role in value-based medicine.


Asunto(s)
Pediatría , Calidad de Vida , Humanos , Niño , Ecosistema , Atención a la Salud , Medición de Resultados Informados por el Paciente
18.
J Vis Exp ; (190)2022 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-36533846

RESUMEN

Retinal degeneration, such as age-related macular degeneration (AMD), is a leading cause of blindness worldwide. A myriad of approaches have been undertaken to develop regenerative medicine-based therapies for AMD, including stem cell-based therapies. Rodents as animal models for retinal degeneration are a foundation for translational research, due to the broad spectrum of strains that develop retinal degeneration diseases at different stages. However, mimicking human therapeutic delivery of subretinal implants in rodents is challenging, due to anatomical differences such as lens size and vitreous volume. This surgical protocol aims to provide a guided method for transplanting implants into the subretinal space in rats. A user-friendly comprehensive description of the critical steps has been included. This protocol has been developed as a cost-efficient surgical procedure for reproducibility across different preclinical studies in rats. Proper miniaturization of a human-sized implant is required prior to conducting the surgical experiment, which includes adjustments to the dimensions of the implant. An external approach is used instead of an intravitreal procedure to deliver the implant to the subretinal space. Using a small sharp needle, a scleral incision is performed in the temporal superior quadrant, followed by paracentesis to reduce intraocular pressure, thereby minimizing resistance during the surgical implantation. Next, a balanced salt solution (BSS) injection through the incision is carried out to achieve focal retinal detachment (RD). Lastly, insertion and visualization of the implant into the subretinal space are conducted. Post-operative assessment of the subretinal placement of the implant includes imaging by spectral domain optical coherence tomography (SD-OCT). Imaging follow-ups ascertain the subretinal stability of the implant, before the eyes are harvested and fixated for histological analysis.


Asunto(s)
Degeneración Macular , Degeneración Retiniana , Humanos , Ratas , Animales , Degeneración Retiniana/cirugía , Degeneración Retiniana/patología , Reproducibilidad de los Resultados , Modelos Animales de Enfermedad , Degeneración Macular/terapia , Tomografía de Coherencia Óptica/métodos
19.
Artículo en Inglés | MEDLINE | ID: mdl-36343006

RESUMEN

Ultrasound neuromodulation is an emerging technology. A significant amount of effort has been devoted to investigating the feasibility of noninvasive ultrasound retinal stimulation. Recent studies have shown that ultrasound can activate neurons in healthy and degenerated retinas. Specifically, high-frequency ultrasound can evoke localized neuron responses and generate patterns in visual circuits. In this review, we recapitulate pilot studies on ultrasound retinal stimulation, compare it with other neuromodulation technologies, and discuss its advantages and limitations. An overview of the opportunities and challenges to develop a noninvasive retinal prosthesis using high-frequency ultrasound is also provided.


Asunto(s)
Retina , Prótesis Visuales , Retina/diagnóstico por imagen , Retina/fisiología , Ultrasonografía
20.
Dent J (Basel) ; 10(9)2022 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-36135162

RESUMEN

The use of herbal medicine in dentistry has grown exponentially over time. Currently, herbal medicine is considered an effective oral hygiene aid. The objective of the current study is to assess the anti-plaque efficiency and reduction of gingival bleeding of betel leaf and miswak (Salvadora persica) toothpaste. This randomized clinical cross-over pilot study enrolled 60 individuals with mild gingivitis. They were segregated into two groups by drawing lots. The study lasted 20 days and included a two-week washout period between miswak and betel leaf toothpaste. The gingival and plaque index were measured at specific time intervals during the research period. The results revealed that betel leaf and miswak herbal toothpaste significantly decreased plaque index. Nevertheless, betel leaf toothpaste caused a more significant reduction in gingival bleeding scores (p < 0.001) when compared to miswak (p = 0.007). No significant decrease in gingival and plaque index was seen when subjects were asked to return to their conventional chemical toothpaste. The current study concluded that betel leaf toothpaste displayed a more substantial decrease in gingival bleeding when compared to miswak toothpaste. Additionally, more studies should be done on the therapeutic benefits of betel leaf toothpaste.

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