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1.
Environ Res ; 258: 119248, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38823615

RESUMO

To ensure the structural integrity of concrete and prevent unanticipated fracturing, real-time monitoring of early-age concrete's strength development is essential, mainly through advanced techniques such as nano-enhanced sensors. The piezoelectric-based electro-mechanical impedance (EMI) method with nano-enhanced sensors is emerging as a practical solution for such monitoring requirements. This study presents a strength estimation method based on Non-Destructive Testing (NDT) Techniques and Long Short-Term Memory (LSTM) and artificial neural networks (ANNs) as hybrid (NDT-LSTMs-ANN), including several types of concrete strength-related agents. Input data includes water-to-cement rate, temperature, curing time, and maturity based on interior temperature, allowing experimentally monitoring the development of concrete strength from the early steps of hydration and casting to the last stages of hardening 28 days after the casting. The study investigated the impact of various factors on concrete strength development, utilizing a cutting-edge approach that combines traditional models with nano-enhanced piezoelectric sensors and NDT-LSTMs-ANN enhanced with nanotechnology. The results demonstrate that the hybrid provides highly accurate concrete strength estimation for construction safety and efficiency. Adopting the piezoelectric-based EMI technique with these advanced sensors offers a viable and effective monitoring solution, presenting a significant leap forward for the construction industry's structural health monitoring practices.

3.
Oral Maxillofac Surg ; 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38602585

RESUMO

PURPOSE: This study investigates the motivations for orthognathic surgery and assesses the quality of life (QoL) and satisfaction among patients treated at a hospital over 12 months. METHODS: We employed an Arabic version of the Orthognathic Quality of Life Questionnaire (OQLQ), used pre-surgery and at 2 weeks, 3 months, and 6 months post-surgery. This included demographic data, the OQLQ, and visual analogue scales (VAS). The OQLQ, originally by Cunningham et al., was translated and adapted by Al-Asfour et al. Additional validated questions were added to both pre- and post-operative surveys. RESULTS: Of 136 participants (51 males, 85 females, average age 25.1), most underwent surgery for facial aesthetics (85.2%) and bite correction (57.3%). Treatments included various osteotomies. OQLQ scores significantly dropped from 63.3% pre-surgery to 23% at 6 months, showing QoL improvement. 97.8% reported better psychological status post-surgery (p = 0.0001), with 94.1% satisfaction at 6 months (p = 0.0001). CONCLUSION: The orthognathic surgery yielded positive outcomes in functional and psychological aspects, leading to high satisfaction and improved QoL in patients with dentofacial deformity.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38458653

RESUMO

OBJECTIVES: To evaluate the value of Spinal Instability Neoplastic Score (SINS) in patients with spine metastasis who subsequently developed or did not develop metastatic spinal cord compression (MSCC). METHODS: In this single institutional retrospective descriptive observational study, of 589 patients with MSCC who were referred for radiotherapy, 34 patients (with 41 compression sites) met the inclusion criteria: availability of diagnostic MRI spine pre-development of MSCC (MRI-1) and at the time of MSCC development (MRI-2) (CordGroup).For comparison, NoCordGroup consisted of 152 patients (160 sites) treated with radiotherapy to spinal metastases. SINS was compared between the two groups. RESULTS: In CordGroup, the median interval between MRI-1 and MRI-2 was 11 weeks. The median SINS was 8 (range: 4-14) and 9 (range: 7-14) on MRI-1 and MRI-2, respectively. In NoCordGroup, the median SINS was 6 (range: 4-10). CONCLUSIONS: Our study showed a trend in difference in SINS value between the two groups. This difference should be a subject of future prospective research in this patient population with poor survival.

5.
Int J Pharm ; 655: 123998, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38490401

RESUMO

The mucus is a defensive barrier for different drug-loaded systems. To overcome this obstacle, the crucial factor is the surface charge. Due to mucus negative charge behavior; it was revealed that negatively charged formulations can move across mucus, whereas positively charged nanoformulations could not diffuse via mucus due to interactions. However, cellular intake of negatively charged nanoformulations to the epithelium by endocytosis is less prominent as compared to positively charged carriers. Self-emulsifying drug delivery systems (SEDDS) improve the drug permeability of drugs, especially which have poor oral drug solubility. Moreover, SEDDS have the ability to reduce the degradation of drugs in the GI tract. Currently, drug carrier systems that can shift zeta potential from negative to positive were developed. The benefits of inducing zeta potential changing approach are that negatively charged nanoformulations permeate quickly across the mucus and surface charges reversed to positive at epithelium surface to increase cellular uptake. Among various systems of drug delivery, zeta potential changing SEDDS seem to signify a promising approach as they can promptly diffuse over mucus due to their smaller size and shape distortion ability. Due to such findings, mucus permeation and drug diffusion may improve by the mixture of the zeta potential changing approach and SEDDS.


Assuntos
Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Humanos , Emulsões , Disponibilidade Biológica , Células CACO-2 , Administração Oral , Solubilidade
6.
J Emerg Med ; 66(2): 192-196, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38278678

RESUMO

BACKGROUND: Eye-related symptoms are a common presentation in the emergency department (ED). The cases range from simple viral conjunctivitis to trauma-related eye injuries. One pathological condition that could lead to vision loss is retinal artery occlusion (RAO). Evaluating a patient with an eye symptom requires thorough eye examination and advanced imaging in certain instances. Consultation with an ophthalmologist is also necessary for cases that require treatment recommendations and further testing. In the ED, point-of-care ultrasound (POCUS) is a commonly used diagnostic tool that can be used for ocular examination. CASE REPORT: We reported a case of a 60-year-old man who presented with painless partial right-eye vision loss. POCUS showed decreased flow in the right central retinal artery with an area of the pale retina seen on the image from the retinal camera, suggesting a possible branch RAO. Further examination with POCUS showed plaque formation at the carotid bifurcation, a potential cause of the patient's symptoms. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians and other providers should be encouraged to use POCUS to diagnose eye symptoms accurately and promptly. Abnormal findings will prompt immediate specialty consult and early appropriate management. Our case and other reported cases highlight POCUS's reliability and rapid diagnostic ability.


Assuntos
Sistemas Automatizados de Assistência Junto ao Leito , Testes Imediatos , Masculino , Humanos , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Ultrassonografia/métodos , Cegueira/etiologia , Serviço Hospitalar de Emergência
7.
Environ Res ; 236(Pt 1): 116776, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37517486

RESUMO

A steadily increasing production volume of nanoparticles reflects their numerous industrial and domestic applications. These economic successes come with the potential adverse effects on natural systems that are associated with their presence in the environment. Biological activities and effects of nanoparticles are affected by their entry method together with their specificities like their size, shape, charge, area, and chemical composition. Particles can be classified as safe or dangerous depending on their specific properties. As both aquatic and terrestrial systems suffer from organic and inorganic contamination, nanoparticles remain a sink for these contaminants. Researching the sources, synthesis, fate, and toxicity of nanoparticles has advanced significantly during the last ten years. We summarise nanoparticle pathways throughout the ecosystem and their interactions with beneficial microorganisms in this research. The prevalence of nanoparticles in the ecosystem causes beneficial microorganisms to become hazardous to their cells, which prevents the synthesis of bioactive molecules from undergoing molecular modifications and diminishes the microbe population. Recently, observed concentrations in the field could support predictions of ambient concentrations based on modeling methodologies. The aim is to illustrate the beneficial and negative effects that nanoparticles have on aqueous and terrestrial ecosystems, as well as the methods utilized to reduce their toxicity.

8.
Sultan Qaboos Univ Med J ; 22(4): 479-485, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36407700

RESUMO

Objectives: This study aimed to assess the effectiveness of the new traffic law enforcement regulations (TLERs) on the incidence and severity of maxillofacial injuries in Oman, as road traffic accidents (RTAs) are the main cause of facial injuries in Oman. Methods: A retrospective longitudinal analytic study was conducted at three tertiary care hospitals in Muscat, Oman. All patients with RTA-related maxillofacial injuries during a five-year period from January 2005 to December 2009 (before the new TLERs) and the five-year period from January 2015 to December 2019 (after the new TLERs) were included in the study. Results: A total of 1,127 patients were included in the study. Of these, 646 (57.3%) patients sustained RTA-related maxillofacial injuries before the implementation of the new TLERs compared to 481 (42.7%) after the introduction of TLERs. No significant gender-based difference was found between the two study periods. The incidence of injury before the implementation of the new TLERs was 22.7 per 100,000 population, which then reduced significantly to 11 per 100,000 after the TLERs were implemented. Overall, the mean facial injury severity score reduced significantly, from 3.2 to 2.3, after the implementation of the new TLERs. Conclusions: The findings of this study indicate that the newly introduced TLERs have resulted in a reduction in the incidence and severity of RTA-related maxillofacial injuries. Continuous improvement and reinforcement of TLERs will further help reduce the burden of these injuries to society in general and health services in particular.


Assuntos
Aplicação da Lei , Traumatismos Maxilofaciais , Humanos , Incidência , Estudos Retrospectivos , Acidentes de Trânsito , Traumatismos Maxilofaciais/epidemiologia , Traumatismos Maxilofaciais/etiologia
9.
Radiol Case Rep ; 17(10): 3801-3805, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35965933

RESUMO

The novel coronavirus infection (COVID-19) caused by the SARS-CoV-2 virus is a relatively recent infection that has resulted in a global pandemic, appearing first at the end of 2019. While initially presenting as a predominantly respiratory disease, with a classical picture of fever, dry cough, dyspnea and, in some cases anosmia and ageusia, recent cases have shown increasingly atypical and more systemic manifestation of the disease. A precise understanding of the extent and pathophysiology of COVID-19 remains underway to this day, particularly concerning its behavior in the pediatric population. Moreover, there has been an increasing number of COVID-19 reports with neurological complications and manifestations, prompting inquiry into neuroinvasion. Postulations include indirect invasion through a surge of inflammatory mediators "cytokine storm" and subsequent widespread endothelial injury; and direct neural tropism. We report the case of a previously healthy 12-year-old male presenting with acute right-sided hemiparesis, new-onset seizures and a generalized petechial rash. Laboratory tests revealed elevated inflammatory markers and radiological investigations confirmed an evolving left middle cerebral artery (MCA) infarct and large vessel vasculitis. Testing for SARS-CoV-2 infection was positive.

10.
Oman Med J ; 36(4): e285, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34367686

RESUMO

Condylar hyperplasia (CH) is a rare idiopathic condition affecting the mandibular condyle where the growth of the condylar head and/or neck continues beyond the normal growth period. The disorder presents clinically as facial asymmetry and occlusal discrepancy. Here, we present two cases of CH managed at our centers between 2012 and 2017 with a successful outcome. We highlight the clinical presentation, investigation, and surgical management and give a brief literature review.

11.
Oman Med J ; 36(1): e227, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33692909

RESUMO

Tenosynovial giant cell tumor (TGCT) is a benign soft-tissue neoplasm that rarely occurs in the craniofacial region. We report a case of a 27-year-old male who presented to our unit in September 2017 with severe temporomandibular joint (TMJ) pain and progressive limitation opening his mouth. Based on clinical and imaging examinations, a well-defined soft tissue lesion was identified within the right infratemporal fossa, causing pressure on the TMJ and the surrounding structures. The lesion was surgically excised through trans-mandibular and endoscopic approaches. Histopathology diagnosis revealed a rare chondroid subset of TGCT. At 18 months follow-up, the patient showed resolution of the jaw pain, good functional and esthetic outcomes, and no evidence of recurrence.

12.
Sultan Qaboos Univ Med J ; 20(3): e362-e367, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33110654

RESUMO

ß-thalassaemia major is an autosomal recessive form of haemoglobinopathy that is characterised by complete lack of production of the ß-chains resulting in multiple complications that include severe anaemia, failure to thrive and skeletal abnormalities. Facial deformities induced by ß-thalassaemia major are rare and are very challenging to treat from a surgical point of view. We report a 33-year-old female patient with ß-thalassaemia major who presented to the Dental & Maxillofacial Surgery Department, Sultan Qaboos University Hospital, Muscat, Oman, in 2017 with gross dentofacial skeletal deformity contributing to her psychosocial issues. The facial deformity was corrected surgically by excision of the enlarged maxilla, modified Le Fort I osteotomy and advancement genioplasty. This case highlights the pre-operative preparation, surgical management, encountered complications and treatment outcome within 24 months of follow-up.


Assuntos
Deformidades Dentofaciais/cirurgia , Osteotomia de Le Fort/métodos , Talassemia beta/complicações , Adulto , Deformidades Dentofaciais/fisiopatologia , Feminino , Mentoplastia/normas , Humanos , Omã , Osteotomia de Le Fort/normas , Talassemia beta/cirurgia
13.
Neurosurgery ; 85(5): E860-E869, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31173150

RESUMO

BACKGROUND: Cavity stereotactic radiotherapy has emerged as a standard option following resection of brain metastases. However, the optimal approach with either single-fraction or hypofractionated stereotactic radiotherapy (HSRT) remains a significant question. OBJECTIVE: To report outcomes for 5-fraction HSRT to the surgical cavity, based on contouring according to a recently reported international consensus guideline. METHODS: Patients treated with cavity HSRT were identified from a prospective institutional database. Local brain control (LC), distant brain failure (DBF), leptomeningeal disease (LMD), and overall survival rates were determined. Univariate and multivariable analyses were performed on potential predictive factors. RESULTS: One hundred thirty-seven cavities in 122 patients were treated at a median total dose of 30 Gy (range, 25-35 Gy). The median follow-up was 16 mo (range, 1-60 mo). Nonsmall cell lung cancer was the most common histology (44%), followed by breast cancer (21%). In 57% of surgical cavities, the preoperative tumor diameter was >3 cm. One-year LC, DBF, LMD, and overall survival rates were 84%, 45%, 22%, and 62%, respectively. Multivariable analyses identified colorectal (hazard ratio [HR] 4.1, P = .0066) and melanoma (HR 2.4, P = .012) metastases as predictors of local recurrence; preoperative tumor diameter >2 cm (HR 8.9, P = .012) and absence of targeted therapy (HR 4.4, P = .03) as predictors of DBF; and breast cancer histology (HR 2.1, P = .05) and subtotal resection (HR 2.6, P = .009) as predictors of LMD. Symptomatic radiation necrosis was observed in 7 patients (6%). CONCLUSION: High rates of LC were observed following this 5-fraction HSRT regimen. Superiority as compared to single-fraction SRS requires a randomized trial.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Hipofracionamento da Dose de Radiação , Radiocirurgia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/radioterapia , Neoplasias da Mama/secundário , Estudos de Coortes , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/secundário , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/radioterapia , Recidiva Local de Neoplasia/secundário , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
14.
Sultan Qaboos Univ Med J ; 19(4): e364-e368, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31897321

RESUMO

Traumatic maxillary artery pseudoaneurysm is an uncommonly reported complication in the field of oral and maxillofacial surgery. It is usually discovered incidentally, either early after trauma or weeks-to-months later. Quick recognition and prompt management are essential to avoid devastating consequences. In this paper, we report three uncommon cases of maxillary artery pseudoaneurysm recognised during the surgical management of maxillofacial injuries in Muscat, Oman. All cases presented as sudden brisk bleeding during the intraoperative surgical repair and were subsequently diagnosed and successfully managed by endovascular embolisation with platinum coils. This case report highlights the clinical presentation, diagnosis and management of maxillary artery pseudoaneurysm, in addition to a brief review of the literature.


Assuntos
Falso Aneurisma/etiologia , Embolização Terapêutica/métodos , Face/irrigação sanguínea , Artéria Maxilar/fisiopatologia , Traumatismos Maxilofaciais/complicações , Hemorragia Pós-Operatória/etiologia , Adulto , Falso Aneurisma/diagnóstico por imagem , Falso Aneurisma/cirurgia , Humanos , Masculino , Traumatismos Maxilofaciais/diagnóstico por imagem , Traumatismos Maxilofaciais/cirurgia , Hemorragia Pós-Operatória/diagnóstico por imagem , Hemorragia Pós-Operatória/cirurgia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
15.
Sultan Qaboos Univ Med J ; 18(3): e379-e382, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30607282

RESUMO

The surgical management of paediatric patients with temporomandibular joint (TMJ) ankylosis, mandibular retrognathia and obstructive sleep apnoea (OSA) is challenging. We report a nine-year-old boy who presented to the Department of Oral Health, Sultan Qaboos University Hospital, Muscat, Oman, in 2016 with complaints of limited mouth opening, loud snoring and excessive daytime sleepiness. He was diagnosed with TMJ ankylosis, mandibular retrognathia and severe OSA. The patient initially underwent mandibular distraction and, subsequently, release of the TMJ ankylosis and rib graft reconstruction. The overall patient outcome was successful, with improvement in OSA-related symptoms, good facial symmetry and adequate mouth opening.


Assuntos
Anquilose/diagnóstico , Retrognatismo/diagnóstico , Apneia Obstrutiva do Sono/diagnóstico , Transtornos da Articulação Temporomandibular/diagnóstico , Anquilose/fisiopatologia , Anquilose/cirurgia , Criança , Humanos , Masculino , Mandíbula/cirurgia , Omã , Procedimentos Cirúrgicos Bucais/métodos , Retrognatismo/fisiopatologia , Apneia Obstrutiva do Sono/fisiopatologia , Transtornos da Articulação Temporomandibular/fisiopatologia , Transtornos da Articulação Temporomandibular/cirurgia
16.
J Neurosurg Spine ; 25(5): 646-653, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27341054

RESUMO

OBJECTIVE This study is a multi-institutional pooled analysis specific to imaging-based local control of spinal metastases in patients previously treated with conventional external beam radiation therapy (cEBRT) and then treated with re-irradiation stereotactic body radiotherapy (SBRT) to the spine as salvage therapy, the largest such study to date. METHODS The authors reviewed cases involving 215 patients with 247 spinal target volumes treated at 7 institutions. Overall survival was calculated on a patient basis, while local control was calculated based on the spinal target volume treated, both using the Kaplan-Meier method. Local control was defined as imaging-based progression within the SBRT target volume. Equivalent dose in 2-Gy fractions (EQD2) was calculated for the cEBRT and SBRT course using an α/ß of 10 for tumor and 2 for both spinal cord and cauda equina. RESULTS The median total dose/number of fractions of the initial cEBRT was 30 Gy/10. The median SBRT total dose and number of fractions were 18 Gy and 1, respectively. Sixty percent of spinal target volumes were treated with single-fraction SBRT (median, 16.6 Gy and EQD2/10 = 36.8 Gy), and 40% with multiple-fraction SBRT (median 24 Gy in 3 fractions, EQD2/10 = 36 Gy). The median time interval from cEBRT to re-irradiation SBRT was 13.5 months, and the median duration of patient follow-up was 8.1 months. Kaplan-Meier estimates of 6- and 12-month overall survival rates were 64% and 48%, respectively; 13% of patients suffered a local failure, and the 6- and 12-month local control rates were 93% and 83%, respectively. Multivariate analysis identified Karnofsky Performance Status (KPS) < 70 as a significant prognostic factor for worse overall survival, and single-fraction SBRT as a significant predictive factor for better local control. There were no cases of radiation myelopathy, and the vertebral compression fracture rate was 4.5%. CONCLUSIONS Re-irradiation spine SBRT is effective in yielding imaging-based local control with a clinically acceptable safety profile. A randomized trial would be required to determine the optimal fractionation.


Assuntos
Radiocirurgia/métodos , Reirradiação/métodos , Terapia de Salvação/métodos , Neoplasias da Coluna Vertebral/secundário , Neoplasias da Coluna Vertebral/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Seguimentos , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Radiocirurgia/efeitos adversos , Dosagem Radioterapêutica , Reirradiação/efeitos adversos , Terapia de Salvação/efeitos adversos , Neoplasias da Coluna Vertebral/mortalidade , Coluna Vertebral/cirurgia , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
17.
Neurooncol Pract ; 3(1): 48-58, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31579521

RESUMO

Spinal metastases are increasingly becoming a focus of attention with respect to treating with locally "ablative" intent, as opposed to locally "palliative" intent. This is due to increasing survival rates among patients with metastatic disease, early detection as a result of increasing availability of spinal MRI, the recognition of the oligometastatic state as a distinct sub-group of favorable metastatic patients and the advent of stereotactic body radiotherapy (SBRT). Although conventionally fractionated radiation therapy has been utilized for decades, the rates of complete pain relief and local control for complex tumors are sub-optimal. SBRT has the advantage of delivering high total doses in few fractions (typically, 24 Gy in 1 or 2 fractions to 30-45 Gy in 5 fractions) that can be considered "ablative". With mature clinical experience emerging among early adopters, we are realizing beyond efficacy the limitations of spine SBRT. In particular, toxicities such as vertebral compression fracture, and epidural disease progression as the most common pattern of local tumor progression. As a result, the multidisciplinary evaluation of cases prior to SBRT is emphasized with the intent to identify patients who could benefit from surgical stabilization or down-staging of epidural disease. The purpose of this review is to provide an overview of the current literature with respect to outcomes, technical details for safe delivery, patient selection criteria, common and uncommon side effects of therapy, and the increasing use of minimally invasive surgical techniques that can improve both safety and local control.

18.
Sultan Qaboos Univ Med J ; 15(4): e554-8, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26629387

RESUMO

Temporomandibular joint (TMJ) ankylosis as a complication of neonatal septic arthritis is rarely reported in the literature. We report two clinical cases of unilateral TMJ ankylosis occurring in paediatric patients subsequent to neonatal septic arthritis. The first case was a 15-month-old male infant who presented to the Sultan Qaboos University Hospital, Muscat, Oman, in May 2010. According to the published English scientific literature, he is the youngest person yet to be diagnosed with this condition. The second case was a five-year-old female who presented to the Al-Nahda Hospital, Muscat, Oman, in October 2011. Both cases presented with facial asymmetry and trismus. They subsequently underwent gap arthroplasty and interpositional temporalis muscle and fascia grafts which resulted in an immediate improvement in mouth opening. Postoperatively, the patients underwent active jaw physiotherapy which was initially successful. Both patients were followed up for a minimum of two years following their surgeries.

19.
J Neuropathol Exp Neurol ; 72(11): 1016-28, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24128679

RESUMO

Hereditary spastic paraplegias (HSPs) are characterized by progressive spasticity and weakness in the lower extremities that result from length-dependent central to peripheral axonal degeneration. Mutations in the non-imprinted Prader-Willi/Angelman syndrome locus 1 (NIPA1) transmembrane protein cause an autosomal dominant form of HSP (SPG6). Here, we report that transgenic (Tg) rats expressing a human NIPA1/SPG6 mutation in neurons (Thy1.2-hNIPA1) show marked early onset behavioral and electrophysiologic abnormalities. Detailed morphologic analyses reveal unique histopathologic findings, including the accumulation of tubulovesicular organelles with endosomal features that start at axonal and dendritic terminals, followed by multifocal vacuolar degeneration in both the CNS and peripheral nerves. In addition, the NIPA1 mutation in the spinal cord from older Tg rats results in an increase in bone morphogenetic protein type II receptor expression, suggesting that its degradation is impaired. This Thy1.2-hNIPA1 Tg rat model may serve as a valuable tool for understanding endosomal trafficking in the pathogenesis of a subgroup of HSP with an abnormal interaction with bone morphogenetic protein type II receptor, as well as for developing potential therapeutic strategies for diseases with axonal degeneration and similar pathogenetic mechanisms.


Assuntos
Axônios/patologia , Córtex Cerebral/patologia , Proteínas de Membrana/genética , Degeneração Neural/patologia , Neurônios/patologia , Paraplegia Espástica Hereditária/patologia , Animais , Axônios/metabolismo , Comportamento Animal/fisiologia , Córtex Cerebral/metabolismo , Modelos Animais de Doenças , Endossomos/genética , Endossomos/metabolismo , Endossomos/patologia , Proteínas de Membrana/metabolismo , Destreza Motora/fisiologia , Degeneração Neural/genética , Degeneração Neural/metabolismo , Neurônios/metabolismo , Transporte Proteico/genética , Ratos , Ratos Transgênicos , Paraplegia Espástica Hereditária/genética , Paraplegia Espástica Hereditária/metabolismo , Medula Espinal/metabolismo , Medula Espinal/patologia , Vacúolos/metabolismo , Vacúolos/patologia
20.
J Med Case Rep ; 6: 295, 2012 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-22973995

RESUMO

INTRODUCTION: Primary squamous cell carcinoma of the pancreas is a rare tumor with poor prognosis and is found in the literature only as case reports. The optimal management course remains poorly defined. We present a case of primary basaloid squamous cell carcinoma of the pancreas metastatic to the liver, which was treated with surgery and systemic chemotherapy. Our patient survived for 15 months: the longest survival reported in the literature to date. CASE PRESENTATION: A 70-year-old Caucasian man presented to hospital with a three-month history of weight loss, pruritus and icterus. Imaging studies confirmed the presence of an operable mass lesion in the head of the pancreas. Following a pancreaticoduodenectomy, histology results led us to make a diagnosis of squamous cell carcinoma. Postoperative restaging showed multiple metastases in the liver. He underwent palliative systemic chemotherapy with cisplatin and 5-fluorouracil achieving partial response and an excellent quality of life. He then went on to start second-line chemotherapy, but unfortunately died of sepsis soon thereafter. CONCLUSIONS: This case report emphasizes that achievement of a worthwhile objective and symptomatic palliative response is possible using platinum-based chemotherapy in squamous cell carcinoma of the pancreas.

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