Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 1.695
Filter
1.
J Plast Reconstr Aesthet Surg ; 95: 340-348, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38959620

ABSTRACT

BACKGROUND: Amyloidosis is characterized by extracellular amyloid protein deposition. When amyloidosis intersects with basal cell carcinoma (BCC), it introduces complex diagnostic challenges. This study explored the overlap between primary localized cutaneous amyloidosis (PLCA) and BCC, examining amyloid deposits in BCC, systemic amyloidosis risk in PLCA, and various treatment methods. METHODS: Two case studies were discussed, followed by a literature review, in which PubMed, Web of Science, EMBASE, and the Cochrane Library databases were utilized. The search, covering studies from infinity up to January 2024, focused on "cutaneous amyloidosis," "basal cell carcinoma," and related terms. Articles in English detailing the clinical presentation, diagnostic methods, treatment, and outcomes of cutaneous amyloidosis mimicking BCC were included. Data extraction and synthesis were performed by two independent reviewers. CASE SERIES: This study highlighted two cases exemplifying the complexity of diagnosing BCC and PLCA. The first case (a 64-year-old with a nodule on the cheek) and the second (a 67-year-old with a nodular lesion on the upper lip cheek) were initially suspected as BCC and were later identified as PLCA upon histopathological examination. DISCUSSION: The diagnosis of amyloidosis within BCC nodules remains a diagnostic challenge. Although their coexistence is relatively prevalent, their local recurrence rates remain debatable. Various diagnostic and therapeutic approaches have been suggested, such as topical creams and phototherapy. However, none have garnered conclusive and consistent evidence to establish reliable clinical application. CONCLUSION: The findings emphasized the importance of considering alternative pathologies in differential diagnoses. Future research should focus on understanding systemic amyloidosis risks and optimizing care for both conditions.

2.
Proc Natl Acad Sci U S A ; 121(28): e2403763121, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38968111

ABSTRACT

Advancing the mechanistic understanding of absence epilepsy is crucial for developing new therapeutics, especially for patients unresponsive to current treatments. Utilizing a recently developed mouse model of absence epilepsy carrying the BK gain-of-function channelopathy D434G, here we report that attenuating the burst firing of midline thalamus (MLT) neurons effectively prevents absence seizures. We found that enhanced BK channel activity in the BK-D434G MLT neurons promotes synchronized bursting during the ictal phase of absence seizures. Modulating MLT neurons through pharmacological reagents, optogenetic stimulation, or deep brain stimulation effectively attenuates burst firing, leading to reduced absence seizure frequency and increased vigilance. Additionally, enhancing vigilance by amphetamine, a stimulant medication, or physical perturbation also effectively suppresses MLT bursting and prevents absence seizures. These findings suggest that the MLT is a promising target for clinical interventions. Our diverse approaches offer valuable insights for developing next generation therapeutics to treat absence epilepsy.


Subject(s)
Disease Models, Animal , Epilepsy, Absence , Animals , Epilepsy, Absence/physiopathology , Mice , Thalamus/physiopathology , Neurons/metabolism , Neurons/physiology , Optogenetics , Large-Conductance Calcium-Activated Potassium Channels/metabolism , Deep Brain Stimulation/methods , Male , Midline Thalamic Nuclei/physiology
3.
Ann Transl Med ; 12(3): 51, 2024 Jun 10.
Article in English | MEDLINE | ID: mdl-38911569

ABSTRACT

Background: The abdominal donor site is the most common flap used for breast reconstruction, with flap necrosis a feared complication. The technique of surgical 'delay' involves the inducing of relative ischemia to promote neovascularisation, amongst other metabolic adaptations, and has been used to augment flap vascularity and reduce this complication. There is significant variability in the manner in which flap surgery and surgical delay may be performed, such as the vessels ligated, the presence and degree of flap elevation, and the decision to harvest muscle with the flap, amongst other factors. A formal review of techniques, however, has not yet been performed, and there is no consensus as to the optimal technique for surgical delay. Methods: A scoping review of the current literature was undertaken to determine the optimal surgical delay technique in abdominal-based flap surgery. A literature search was conducted across PubMed, Embase, Cochrane, and Medline databases. Data regarding the type of flap surgery, delay techniques, and corresponding clinical outcomes was collected and categorised by technique type. Results: Nine studies met the inclusion criteria and were included for review. Levels of evidence and rates of complications were compared. The range of surgical delay techniques reported in the literature was described. Surgical delay was found to reduce overall complication rates, and the available data suggests it may be particularly beneficial in high-risk patients. Conclusions: The current data support delay as a viable method for reducing rates of complications. Further studies and data are required to compare surgical delay techniques and determine the benefit delay may pose to patients with risk factors.

4.
JPRAS Open ; 41: 25-32, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38868740

ABSTRACT

Background: Atrophic scarring is a severe form-disfiguring sequela of acne, which can lead to negative effect on patients' life. Fractional microplasma radiofrequency (RF) has emerged as a promising modality, leveraging dermal fibroblast remodeling to enhance aesthetic results for scars and hyperpigmentation. This study evaluates the efficacy and safety of high-power fractional microplasma RF for atrophic acne scars, considering patient tolerance to procedural discomfort. Methods: In this prospective study, 95 Chinese patients with atrophic facial acne scars underwent three sessions of fractional microplasma RF treatment, with assessments at 1, 3, and 6 months post-treatment. Patients were categorized based on treatment power: Group A (50-70 W) and Group B (70-85 W). Efficacy was determined by three independent dermatologists using digital photographs and Echelle d'Evaluation Clinique des Cicatrices d'Acné (ECCA) scores, and patient-reported outcomes gauged satisfaction levels. Results: Eighty-six patients completed the study. Significant improvements were observed, with a reduction in ECCA scores from 107.21 to 42.27 (P<0.05), demonstrating notable scar amelioration across both groups, albeit with a superior outcome in Group B. All patients experienced transient side effects such as pain, erythema, and edema, deemed tolerable with no long-term adverse effects reported. The treatment was well-received, with high satisfaction rates, underscoring its efficacy and acceptable safety profile. Conclusion: Fractional microplasma RF therapy, particularly at higher power settings, is an effective and safe option for treating atrophic acne scars, offering significant aesthetic improvement with manageable discomfort. This modality presents a valuable addition to acne scar management strategies, especially for patients with darker skin tones seeking minimal downtime and reduced risk of hyperpigmentation.

5.
Hand Ther ; 29(2): 44-51, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38827650

ABSTRACT

Introduction: The Ten Test (TT) is a touch threshold test that quantifies sensory discrimination by comparing an injured area with a contralateral uninjured area. It's quick, simple, equipment-free and repeatable. However, as a subjective measure, the TT's reliability and applicability need further investigation. This review aimed to investigate if the TT has superior inter- and intra-examiner reliability compared to the widely accepted Weinstein Enhanced Sensory Test (WEST) in a human population of all ages. Methods: A systematic search was conducted on major databases from January 1997 to September 2023 and adhered to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol. Outcomes were assessed with a narrative approach. The included articles were critically appraised according to the Quality Assessment of Diagnostic Accuracy Studies two tool. Results: This review included five articles. High inter-examiner reliability was demonstrated with intraclass correlation coefficient (ICC) values of 0.91 and 0.95, alongside a kappa statistic of 1, as reported by three distinct studies. Intra-examiner reliability displayed some variance, with one study reporting a significant ICC value in four out of six instances. Two studies corroborated that the TT results corresponded with the findings of WEST, each presenting a Spearman rank coefficient of -0.71. Conclusion: Our findings underscore the TT's high inter-examiner reliability, though its intra-examiner reliability exhibited some inconsistencies. Interestingly, certain studies claimed its superiority over the WEST. To validate the TT's use in the clinical setting, more rigorous studies, particularly those comparing pre-operative TT outcomes with intraoperative nerve damage evaluations, are essential.

6.
J Clin Med ; 13(9)2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38731009

ABSTRACT

Clear cell acanthoma (CCA) and squamous cell carcinoma (SCC) represent distinct entities within dermatological oncology, each posing unique diagnostic and therapeutic challenges. CCA is a rare, benign epidermal growth, often not associated with human papillomavirus (HPV) infection, whereas SCC, a more aggressive form of skin cancer, has been linked to both ultraviolet (UV) exposure and HPV. Understanding the co-occurrence of these conditions in a single patient can enhance diagnostic accuracy and therapeutic outcomes. We report a 64-year-old male who underwent an operation for a verruciform lesion in the right groin, which was diagnosed as HPV-positive CCA alongside keratinised SCC. A literature search across January 2024 revealed limited evidence directly linking HPV to CCA, suggesting a need for further investigation. The speculative association between HPV and CCA warrants deeper exploration, especially considering the potential for HPV to contribute to lesion development through indirect mechanisms. The coexistence of CCA and SCC in an elderly patient presents a unique clinical scenario. This emphasises the need for vigilant diagnosis and tailored treatment strategies, highlighting the gap in understanding the pathogenesis of CCA, particularly its potential association with HPV. Further research is crucial for elucidating the complex interactions governing these conditions and for developing targeted interventions.

7.
JPRAS Open ; 40: 273-285, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38708385

ABSTRACT

Background: Artificial intelligence (AI) has the potential to transform preoperative planning for breast reconstruction by enhancing the efficiency, accuracy, and reliability of radiology reporting through automatic interpretation and perforator identification. Large language models (LLMs) have recently advanced significantly in medicine. This study aimed to evaluate the proficiency of contemporary LLMs in interpreting computed tomography angiography (CTA) scans for deep inferior epigastric perforator (DIEP) flap preoperative planning. Methods: Four prominent LLMs, ChatGPT-4, BARD, Perplexity, and BingAI, answered six questions on CTA scan reporting. A panel of expert plastic surgeons with extensive experience in breast reconstruction assessed the responses using a Likert scale. In contrast, the responses' readability was evaluated using the Flesch Reading Ease score, the Flesch-Kincaid Grade level, and the Coleman-Liau Index. The DISCERN score was utilized to determine the responses' suitability. Statistical significance was identified through a t-test, and P-values < 0.05 were considered significant. Results: BingAI provided the most accurate and useful responses to prompts, followed by Perplexity, ChatGPT, and then BARD. BingAI had the greatest Flesh Reading Ease (34.7±5.5) and DISCERN (60.5±3.9) scores. Perplexity had higher Flesch-Kincaid Grade level (20.5±2.7) and Coleman-Liau Index (17.8±1.6) scores than other LLMs. Conclusion: LLMs exhibit limitations in their capabilities of reporting CTA for preoperative planning of breast reconstruction, yet the rapid advancements in technology hint at a promising future. AI stands poised to enhance the education of CTA reporting and aid preoperative planning. In the future, AI technology could provide automatic CTA interpretation, enhancing the efficiency, accuracy, and reliability of CTA reports.

8.
J Clin Med ; 13(5)2024 Feb 22.
Article in English | MEDLINE | ID: mdl-38592085

ABSTRACT

Background: The medicinal leech has been used in plastic surgery to resolve venous congestion that can threaten the viability of tissue transfer. Within the context of breast surgery, venous congestion is a pertinent consideration for reconstructive and non-reconstructive breast surgery such as mammoplasty and mastopexy. However, leeching is closely associated with complications such as infection, pain, and anaemia. This is the first systematic review that examines the methodology, efficacy, and post therapeutic outcome data across all existing studies on medicinal leeching in breast surgery. Methods: A systematic search of PubMed and Embase databases from their inception to November 2023 was conducted. Inclusion criteria included studies reporting on the use of leeches to resolve venous congestion in any breast surgery. The JBI Critical Appraisal Checklist for Case Series tool was used for bias analysis. Descriptive statistics were undertaken in Microsoft Excel. Results: A total of 18 studies with a combined sample size of 28 were examined, including 4 case series and 14 case reports. Patients mostly underwent reconstructive breast surgery (75%). The median number of leeches used was two, with a median number of three leeching sessions per day and 3 days of leeching. Medicinal leeching successfully prevented the loss of 75% of all tissue transfers. The complication rate was high at 81.14% and mainly included infection and anaemia. Conclusions: Medicinal leeching is an effective method to relieve venous congestion in breast surgery but must be judiciously used within the clinical context of the patient to maximise efficacy and mitigate harm from complications.

9.
Gland Surg ; 13(3): 395-411, 2024 Mar 27.
Article in English | MEDLINE | ID: mdl-38601286

ABSTRACT

Background and Objective: We have witnessed tremendous advances in artificial intelligence (AI) technologies. Breast surgery, a subspecialty of general surgery, has notably benefited from AI technologies. This review aims to evaluate how AI has been integrated into breast surgery practices, to assess its effectiveness in improving surgical outcomes and operational efficiency, and to identify potential areas for future research and application. Methods: Two authors independently conducted a comprehensive search of PubMed, Google Scholar, EMBASE, and Cochrane CENTRAL databases from January 1, 1950, to September 4, 2023, employing keywords pertinent to AI in conjunction with breast surgery or cancer. The search focused on English language publications, where relevance was determined through meticulous screening of titles, abstracts, and full-texts, followed by an additional review of references within these articles. The review covered a range of studies illustrating the applications of AI in breast surgery encompassing lesion diagnosis to postoperative follow-up. Publications focusing specifically on breast reconstruction were excluded. Key Content and Findings: AI models have preoperative, intraoperative, and postoperative applications in the field of breast surgery. Using breast imaging scans and patient data, AI models have been designed to predict the risk of breast cancer and determine the need for breast cancer surgery. In addition, using breast imaging scans and histopathological slides, models were used for detecting, classifying, segmenting, grading, and staging breast tumors. Preoperative applications included patient education and the display of expected aesthetic outcomes. Models were also designed to provide intraoperative assistance for precise tumor resection and margin status assessment. As well, AI was used to predict postoperative complications, survival, and cancer recurrence. Conclusions: Extra research is required to move AI models from the experimental stage to actual implementation in healthcare. With the rapid evolution of AI, further applications are expected in the coming years including direct performance of breast surgery. Breast surgeons should be updated with the advances in AI applications in breast surgery to provide the best care for their patients.

11.
Hand Surg Rehabil ; 43(3): 101694, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38642740

ABSTRACT

OBJECTIVE: De Quervain's tenosynovitis causes pain and impairment of thumb function. Conservative treatments comprise corticosteroid injection and immobilization, and it is unclear which offers greater efficacy. Previous reviews were limited by the small number of included studies; thus an updated review and meta-analysis is warranted. METHODS: A systematic review of the PubMed, Embase, and Web of Science databases was conducted. Randomized control trials comparing corticosteroid injection to immobilization were included. Two authors screened articles, extracted data, and assessed the risk of bias of included studies. Meta-analyses using the random-effects model were conducted, calculating pooled relative risks and mean differences with 95% confidence intervals. RESULTS: 16 studies comprising 1206 patients were included. Corticosteroid injection showed greater treatment success than immobilization (relative risk: 1.61; 95% confidence interval: 1.21-2.15). Combining treatments demonstrated greater efficacy than immobilization (relative risk: 2.15; 95% confidence interval: 1.77-2.62) or injection alone (relative risk: 1.23; 95% confidence interval: 1.12-1.34). Pain and disability scores were lower with injection than immobilization and with combined treatment than with either alone. CONCLUSION: Corticosteroid injection is more effective than immobilization for De Quervain's tenosynovitis, and combining the two treatments provides additional benefit. We recommend corticosteroid injection in first line treatment and immobilization as adjuvant therapy. Further research is required regarding optimal corticosteroid and local anesthetic formulations.


Subject(s)
De Quervain Disease , Humans , De Quervain Disease/drug therapy , De Quervain Disease/therapy , Immobilization , Glucocorticoids/administration & dosage , Adrenal Cortex Hormones/administration & dosage , Adrenal Cortex Hormones/therapeutic use , Injections
12.
Hand (N Y) ; : 15589447241242830, 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38606949

ABSTRACT

BACKGROUND: Clinically recognizing the changes in carpal bone volumes and understanding their implications in predicting osteoarthritis (OA) is crucial in clinical practice This study aimed to explore age-related differences in carpal bone volumes across genders, leveraging computed tomography (CT) wrist scans to create 3D surface models of these bones. METHODS: Carpal bone volumes were calculated using the 3D Slicer software from CT scans obtained from Frankston Hospital and additional datasets from Brown and Auckland Universities. The data were statistically processed using Stata V13. Double-sided P-values < .05 were considered statistically significant. The study was conducted in accordance with the ethical standards laid out in the Declaration of Helsinki. RESULTS: A total of 181 patients were analyzed, and 48% of whom were female. A statistically significant positive Spearman correlation (rho = 0.37-0.611, P <.05) was observed between increasing age and the volume of all surveyed carpal bones (scaphoid, lunate, triquetrum, pisiform, hamate, capitate, and trapezium) across genders. Intrauser and interuser reliabilities for 3D Slicer-generated volumes of trapezium and pisiform bones were statistically significant, with Interclass Correlation Coefficient (ICC) values of 0.86 and 0.95, respectively. CONCLUSION: Trapezial volumes increase with age, potentially due to the presence of OA and consequent osteophyte formation. This pattern is more prevalent among older individuals and women. However, the positive correlation between carpal bone volume and age was consistent across all carpal bones and both genders, regardless of OA presence. These findings suggest that carpal bone volume may naturally increase with age, independent of OA-related changes. LEVEL OF EVIDENCE: III, cohort study.

13.
JPRAS Open ; 40: 206-214, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38633374

ABSTRACT

Introduction: The use of the dorsal hamate as a free osteochondral bone graft or vascularized bone flap has become the mainstay for large, comminuted middle phalanx volar lip fractures. To date, few studies have been conducted in the assessment of donor site morbidity for the hemi-hamate graft or flap, and none have discussed modes of repair or reconstruction of this donor site. Methods: A retrospective analysis of 14 hemi-hamate arthroplasty (HHA) procedures, including 6 vascularized and 8 non-vascularized grafts, from two surgeons was performed. Four hamate defect reconstruction techniques were utilized: no formal reconstruction, autologous bone grafting, gel foam, or synthetic bone substitute. The dorsal capsule was repaired with either extensor retinaculum grafting or by direct closure. Wrist range of motion, pain scores, and radiographic alignment were assessed. Results: At 6 months follow-up, all patients achieved full, pain-free wrist motion compared to the uninjured side, with visual analog scale pain scores of 0. Serial radiographs showed maintained carpal alignment without instability or subluxation. No differences based on the hamate defect reconstruction method or capsular repair technique was demonstrated. Conclusion: Safe return to pain free, unrestricted wrist function is achievable after HHA, regardless of hamate donor site management. Adequate dorsal capsular repair appears critical to prevent instability. Further study is needed to compare techniques, but choice may be guided by surgeon preference in the absence of clear evidence.

14.
Hand (N Y) ; : 15589447241245736, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38654497

ABSTRACT

BACKGROUND: The management of distal radius giant cell tumors (GCTs) remains challenging, and the optimal approach is still a matter of debate. This systematic review and meta-analysis aimed to compare the outcomes of extended curettage and wide resection, the mainstays of treatment. METHODS: Medline (via PubMed), Cochrane Library, Web of Science, Google Scholar, ClinicalTrials.gov, and Embase databases were searched for comparative studies that assessed extended curettage with adjuvant therapy and wide resection with reconstruction in patients with GCTs of the distal radius up to April 2023. Data were collected and analyzed on rates of local recurrence, metastasis, overall complications, and functional outcomes. The Newcastle-Ottawa scale was used to appraise the risk of bias within each study. RESULTS: Fifteen studies (n = 373 patients) were included and analyzed. Patients who underwent curettage were more likely to develop recurrence (risk ratio [RR] = 3.02 [95% confidence interval; CI, 1.87-4.89], P < .01), showed fewer complications (RR = 0.32 [95% CI, 0.21-0.49], P < .01), and showed greater improvement in Visual Analog Scale and lower Disabilities of the Arm, Shoulder, and Hand scores (P < .00001) than those who underwent wide resection. No significant difference was found regarding metastasis (RR = 1.03 [95% CI, 0.38-2.78], P = .95). CONCLUSIONS: Regarding the surgical approach to GCT of the distal radius, curettage with adjuvant therapy was associated with a higher likelihood of recurrence compared with wide resection with reconstruction. Nevertheless, the curettage approach resulted in significantly lower rates of operative complications, decreased pain scores, and better functional outcomes in comparison to the resection group.

15.
bioRxiv ; 2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38464010

ABSTRACT

While deep brain stimulation (DBS) is widely employed for managing motor symptoms in Parkinson's disease (PD), its exact circuit mechanisms remain controversial. To identify the neural targets affected by therapeutic DBS in PD, we analyzed DBS-evoked whole brain activity in female hemi-parkinsonian rats using function magnetic resonance imaging (fMRI). We delivered subthalamic nucleus (STN) DBS at various stimulation pulse repetition rates using optogenetics, allowing unbiased examinations of cell-type specific STN feed-forward neural activity. Unilateral STN optogenetic stimulation elicited pulse repetition rate-dependent alterations of blood-oxygenation-level-dependent (BOLD) signals in SNr (substantia nigra pars reticulata), GP (globus pallidus), and CPu (caudate putamen). Notably, these manipulations effectively ameliorated pathological circling behavior in animals expressing the kinetically faster Chronos opsin, but not in animals expressing ChR2. Furthermore, mediation analysis revealed that the pulse repetition rate-dependent behavioral rescue was significantly mediated by optogenetically induced activity changes in GP and CPu, but not in SNr. This suggests that the activation of GP and CPu are critically involved in the therapeutic mechanisms of STN DBS.

16.
PLoS Comput Biol ; 20(3): e1011833, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38427699

ABSTRACT

BACKGROUND: Peripheral nerve recordings can enhance the efficacy of neurostimulation therapies by providing a feedback signal to adjust stimulation settings for greater efficacy or reduced side effects. Computational models can accelerate the development of interfaces with high signal-to-noise ratio and selective recording. However, validation and tuning of model outputs against in vivo recordings remains computationally prohibitive due to the large number of fibers in a nerve. METHODS: We designed and implemented highly efficient modeling methods for simulating electrically evoked compound nerve action potential (CNAP) signals. The method simulated a subset of fiber diameters present in the nerve using NEURON, interpolated action potential templates across fiber diameters, and filtered the templates with a weighting function derived from fiber-specific conduction velocity and electromagnetic reciprocity outputs of a volume conductor model. We applied the methods to simulate CNAPs from rat cervical vagus nerve. RESULTS: Brute force simulation of a rat vagal CNAP with all 1,759 myelinated and 13,283 unmyelinated fibers in NEURON required 286 and 15,860 CPU hours, respectively, while filtering interpolated templates required 30 and 38 seconds on a desktop computer while maintaining accuracy. Modeled CNAP amplitude could vary by over two orders of magnitude depending on tissue conductivities and cuff opening within experimentally relevant ranges. Conduction distance and fiber diameter distribution also strongly influenced the modeled CNAP amplitude, shape, and latency. Modeled and in vivo signals had comparable shape, amplitude, and latency for myelinated fibers but not for unmyelinated fibers. CONCLUSIONS: Highly efficient methods of modeling neural recordings quantified the large impact that tissue properties, conduction distance, and nerve fiber parameters have on CNAPs. These methods expand the computational accessibility of neural recording models, enable efficient model tuning for validation, and facilitate the design of novel recording interfaces for neurostimulation feedback and understanding physiological systems.


Subject(s)
Evoked Potentials , Nerve Fibers , Rats , Animals , Action Potentials/physiology , Peripheral Nerves , Computer Simulation , Neural Conduction/physiology
17.
Brain Stimul ; 17(2): 365-381, 2024.
Article in English | MEDLINE | ID: mdl-38492885

ABSTRACT

BACKGROUND: Intracortical microstimulation (ICMS) is used to map neuronal circuitry in the brain and restore lost sensory function, including vision, hearing, and somatosensation. The temporal response of cortical neurons to single pulse ICMS is remarkably stereotyped and comprises short latency excitation followed by prolonged inhibition and, in some cases, rebound excitation. However, the neural origin of the different response components to ICMS are poorly understood, and the interactions between the three response components during trains of ICMS pulses remains unclear. OBJECTIVE: We used computational modeling to determine the mechanisms contributing to the temporal response to ICMS in model cortical neurons. METHODS: We implemented a biophysically based computational model of a cortical column comprising neurons with realistic morphology and synapses and quantified the temporal response of cortical neurons to different ICMS protocols. We characterized the temporal responses to single pulse ICMS across stimulation intensities and inhibitory (GABA-B/GABA-A) synaptic strengths. To probe interactions between response components, we quantified the response to paired pulse ICMS at different inter-pulse intervals and the response to short trains at different stimulation frequencies. Finally, we evaluated the performance of biomimetic ICMS trains in evoking sustained neural responses. RESULTS: Single pulse ICMS evoked short latency excitation followed by a period of inhibition, but model neurons did not exhibit post-inhibitory excitation. The strength of short latency excitation increased and the duration of inhibition increased with increased stimulation amplitude. Prolonged inhibition resulted from both after-hyperpolarization currents and GABA-B synaptic transmission. During the paired pulse protocol, the strength of short latency excitation evoked by a test pulse decreased marginally compared to those evoked by a single pulse for interpulse intervals (IPI) < 100 m s. Further, the duration of inhibition evoked by the test pulse was prolonged compared to single pulse for IPIs <50 m s and was not predicted by linear superposition of individual inhibitory responses. For IPIs>50 m s, the duration of inhibition evoked by the test pulse was comparable to those evoked by a single pulse. Short ICMS trains evoked repetitive excitatory responses against a background of inhibition. However, the strength of the repetitive excitatory response declined during ICMS at higher frequencies. Further, the duration of inhibition at the cessation of ICMS at higher frequencies was prolonged compared to the duration following a single pulse. Biomimetic pulse trains evoked comparable neural response between the onset and offset phases despite the presence of stimulation induced inhibition. CONCLUSIONS: The cortical column model replicated the short latency excitation and long-lasting inhibitory components of the stereotyped neural response documented in experimental studies of ICMS. Both cellular and synaptic mechanisms influenced the response components generated by ICMS. The non-linear interactions between response components resulted in dynamic ICMS-evoked neural activity and may play an important role in mediating the ICMS-induced precepts.


Subject(s)
Cerebral Cortex , Electric Stimulation , Models, Neurological , Neurons , Neurons/physiology , Electric Stimulation/methods , Cerebral Cortex/physiology , Cerebral Cortex/cytology , Animals , Computer Simulation
18.
Aesthetic Plast Surg ; 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38528129

ABSTRACT

BACKGROUND: Artificial intelligence (AI) has emerged as a powerful tool in various medical fields, including plastic surgery. This study aims to evaluate the performance of ChatGPT, an AI language model, in elucidating historical aspects of plastic surgery and identifying potential avenues for innovation. METHODS: A comprehensive analysis of ChatGPT's responses to a diverse range of plastic surgery-related inquiries was performed. The quality of the AI-generated responses was assessed based on their relevance, accuracy, and novelty. Additionally, the study examined the AI's ability to recognize gaps in existing knowledge and propose innovative solutions. ChatGPT's responses were analysed by specialist plastic surgeons with extensive research experience, and quantitatively analysed with a Likert scale. RESULTS: ChatGPT demonstrated a high degree of proficiency in addressing a wide array of plastic surgery-related topics. The AI-generated responses were found to be relevant and accurate in most cases. However, it demonstrated convergent thinking and failed to generate genuinely novel ideas to revolutionize plastic surgery. Instead, it suggested currently popular trends that demonstrate great potential for further advancements. Some of the references presented were also erroneous as they cannot be validated against the existing literature. CONCLUSION: Although ChatGPT requires major improvements, this study highlights its potential as an effective tool for uncovering novel aspects of plastic surgery and identifying areas for future innovation. By leveraging the capabilities of AI language models, plastic surgeons may drive advancements in the field. Further studies are needed to cautiously explore the integration of AI-driven insights into clinical practice and to evaluate their impact on patient outcomes. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

19.
Gene Expr Patterns ; : 119357, 2024 Mar 07.
Article in English | MEDLINE | ID: mdl-38460578

ABSTRACT

In most mammals the major site of sex hormone-binding globulin (SHBG) synthesis is the liver wherefrom it is secreted into the bloodstream and is the primary determinant of sex steroid access to target tissues. The minor site of SHBG synthesis is the testis and in lower mammals testicular SHBG has long been known to be synthesized and secreted by Sertoli cells. However, human testicular SHBG is expressed in developing germ cells from an upstream alternative promoter (altP-SHBG). Transcripts arising from this region comprise an alternative first exon (1A) with the resultant protein confined to the acrosomal compartment of the mature spermatozoa. I have dissected the regulatory components of the alternative SHBG promoter and identified motifs that are required for optimal transcriptional activity from this region. Transcriptional activity is driven by two CACCC elements that appear to be functionally redundant. The transcription factor KLF4 interacts with promoter the region spanning these elements in vivo. Knockdown of Klf4 results in decreased altP-SHBG activity, while Klf4 overexpression relieves the effects of knockdown. Based on their shared patterns of expression in vivo, I conclude that KLF4 is a transcriptional regulator of SHBG in male germ cells.

20.
Hear Res ; 443: 108963, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38308936

ABSTRACT

Exposure to brief, intense sound can produce profound changes in the auditory system, from the internal structure of inner hair cells to reduced synaptic connections between the auditory nerves and the inner hair cells. Moreover, noisy environments can also lead to alterations in the auditory nerve or to processing changes in the auditory midbrain, all without affecting hearing thresholds. This so-called hidden hearing loss (HHL) has been shown in tinnitus patients and has been posited to account for hearing difficulties in noisy environments. However, much of the neuronal research thus far has investigated how HHL affects the response characteristics of individual fibres in the auditory nerve, as opposed to higher stations in the auditory pathway. Human models show that the auditory nerve encodes sound stochastically. Therefore, a sufficient reduction in nerve fibres could result in lowering the sampling of the acoustic scene below the minimum rate necessary to fully encode the scene, thus reducing the efficacy of sound encoding. Here, we examine how HHL affects the responses to frequency and intensity of neurons in the inferior colliculus of rats, and the duration and firing rate of those responses. Finally, we examined how shorter stimuli are encoded less effectively by the auditory midbrain than longer stimuli, and how this could lead to a clinical test for HHL.


Subject(s)
Hearing Loss, Noise-Induced , Inferior Colliculi , Humans , Rats , Animals , Inferior Colliculi/physiology , Noise/adverse effects , Auditory Threshold/physiology , Evoked Potentials, Auditory, Brain Stem/physiology , Cochlea
SELECTION OF CITATIONS
SEARCH DETAIL
...