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1.
Sensors (Basel) ; 23(12)2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37420558

RESUMO

Retinal optical coherence tomography (OCT) imaging is a valuable tool for assessing the condition of the back part of the eye. The condition has a great effect on the specificity of diagnosis, the monitoring of many physiological and pathological procedures, and the response and evaluation of therapeutic effectiveness in various fields of clinical practices, including primary eye diseases and systemic diseases such as diabetes. Therefore, precise diagnosis, classification, and automated image analysis models are crucial. In this paper, we propose an enhanced optical coherence tomography (EOCT) model to classify retinal OCT based on modified ResNet (50) and random forest algorithms, which are used in the proposed study's training strategy to enhance performance. The Adam optimizer is applied during the training process to increase the efficiency of the ResNet (50) model compared with the common pre-trained models, such as spatial separable convolutions and visual geometry group (VGG) (16). The experimentation results show that the sensitivity, specificity, precision, negative predictive value, false discovery rate, false negative rate accuracy, and Matthew's correlation coefficient are 0.9836, 0.9615, 0.9740, 0.9756, 0.0385, 0.0260, 0.0164, 0.9747, 0.9788, and 0.9474, respectively.


Assuntos
Aprendizado Profundo , Redes Neurais de Computação , Tomografia de Coerência Óptica/métodos , Retina/diagnóstico por imagem , Valor Preditivo dos Testes
2.
Biomed Chromatogr ; 36(11): e5476, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35918842

RESUMO

A sensitive and simple sample pretreatment method based on a two-phase solvent bar microextraction (SBME) technique coupled with HPLC-diode array detector (DAD) was developed for simultaneous extraction and determination of trace amounts of furosemide and carbamazepine in human urine and plasma samples. The significance of operational factors on carbamazepine and furosemide extraction efficiency % (EE%) was screened using full factorial design (FFD) while central composite design (CCD) was used to model the entire process. A quadratic model was found convenient to correlate the extraction EE% of selected drugs with dominant experimental factors. A Pareto chart was also used to examine the importance of factors on drugs' EE%. The analytical performance of the method in urine and plasma samples demonstrated good linearity (R2 ˃ 0.992) with detection limits ranging from 4.2 to 10.9 µg L-1 , and extraction recovery over 89.45% for both drugs in urine and plasma samples. A comparison against published methods was also performed and the results revealed that the developed method exhibits a confident sensitivity, feasible operation, and simple analysis for both drugs. Finally, the practicability of the validated SBME-HPLC-DAD method was demonstrated by successfully applying it to the analysis of furosemide and carbamazepine in real patient urine samples.


Assuntos
Microextração em Fase Líquida , Benzodiazepinas , Carbamazepina , Cromatografia Líquida de Alta Pressão/métodos , Furosemida , Humanos , Microextração em Fase Líquida/métodos , Solventes
3.
Artigo em Russo | MEDLINE | ID: mdl-35170282

RESUMO

Depressed skull fractures (ping-pong) in the fetus and newborn are associated with birth canal pathology, maternal trauma and birth trauma following instrumental delivery. The authors report a newborn with a depressed skull fracture (ping-pong) who underwent minimally invasive neurosurgical lifting of bone fragment through a burr hole. Strategy and methods of treatment of similar depressed skull fractures were comprehensively discussed. Moreover, the authors proposed a brief algorithm for the use of vacuum systems and various surgical techniques, including follow-up depending on type, cause, size of the fracture and concomitant intracranial lesions.


Assuntos
Fratura do Crânio com Afundamento , Fraturas Cranianas , Humanos , Recém-Nascido , Crânio , Fratura do Crânio com Afundamento/diagnóstico por imagem , Fratura do Crânio com Afundamento/cirurgia , Fraturas Cranianas/diagnóstico por imagem , Fraturas Cranianas/cirurgia , Trepanação
4.
Artigo em Inglês, Russo | MEDLINE | ID: mdl-36534625

RESUMO

Melanotic neuroectodermal tumor of infancy (MNTI) is a neonatal tumor with progressive growth and high recurrence rate. Aggressive growth and localization of tumor often lead to significant cosmetic defects of cranial and facial bones. The authors report MNTI in a 6-month-old boy with lesion of the large fontanel. Total resection was followed by recurrence after 3 weeks. Repeated resection with subsequent radiotherapy was performed. The follow-up period was 6 months after repeated resection. There was no tumor growth throughout this period. Considering this case and world experience, we can conclude that treatment strategy for MNTI is still unclear.


Assuntos
Tumor Neuroectodérmico Melanótico , Masculino , Recém-Nascido , Humanos , Lactente , Tumor Neuroectodérmico Melanótico/patologia , Tumor Neuroectodérmico Melanótico/cirurgia , Crânio/patologia
5.
Cereb Cortex ; 27(8): 4229-4243, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28525604

RESUMO

A description of the spatiotemporal dynamics of human cortical activity during cognitive tasks is a fundamental goal of neuroscience. In the present study, we employed stereo-EEG in order to assess the neural activity during tool-action observation. We recorded from 49 epileptic patients (5502 leads) implanted with intracerebral electrodes, while they observed tool and hand actions. We deconstructed actions into 3 events-video onset, action onset, and tool-object contact-and assessed how different brain regions respond to these events. Video onset, with actions not yet visible, recruited only visual areas. Aligning the responses at action onset, yielded activity in the parietal-frontal manipulation circuit and, selectively for tool actions, in the left anterior supramarginal gyrus (aSMG). Finally, by aligning to the tool-object contact that signals the achievement of the main goal of the observed action, activations were found in SII and dorsal premotor cortex. In conclusion, our data show that during tool-action observation, in addition to the general action observation network there is a selective activation of aSMG, which exhibits internally different patterns of responsiveness. In addition, neural responses selective for the contact between the tool and the object were also observed.


Assuntos
Córtex Cerebral/fisiologia , Percepção de Movimento/fisiologia , Destreza Motora , Adulto , Córtex Cerebral/fisiopatologia , Epilepsia Resistente a Medicamentos/fisiopatologia , Epilepsia Resistente a Medicamentos/cirurgia , Eletrocorticografia , Epilepsias Parciais/fisiopatologia , Epilepsias Parciais/cirurgia , Feminino , Ritmo Gama , Mãos , Humanos , Masculino , Testes Neuropsicológicos , Estimulação Luminosa
6.
Hell J Nucl Med ; 17(3): 165-6, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25397621

RESUMO

Focal tracer uptake in the jaw during conventional bone scintigraphy is a quite frequent finding usually due to dental disease and seldom to other diseases including malignant disease. Methylene diphosphonate-technetium-99m ((99m)Tc-MDP) 3-phase bone scan is considered the most sensitive imaging method for the detection of jaw osteonecrosis at an early stage. This finding can also but seldom be seen in patients undergoing palliative radionuclide treatment for bone metastases. In conclusion, focal jaw lesions are usually benign and of dental origin. In a small percentage of cancer patients of about 4.3%, jaw lesions as diagnosed among 347 cases of various carcinomas may be due to malignancy. Unfortunately, the number of studies is small, most of them are retrospective and few show biopsy results.


Assuntos
Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/diagnóstico por imagem , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/metabolismo , Neoplasias Maxilomandibulares/diagnóstico por imagem , Neoplasias Maxilomandibulares/metabolismo , Compostos Organometálicos/farmacocinética , Compostos Organofosforados/farmacocinética , Diagnóstico Diferencial , Humanos , Achados Incidentais , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Distribuição Tecidual
7.
Eur J Gynaecol Oncol ; 34(2): 197-9, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23781599

RESUMO

The authors describe the occurrence of a 55-year-old female patient presenting with a vulvar melanoma, endometrial polyp, and a prior history of breast carcinoma excised from the left chest wall, radiotherapy, chemotherapy, and tamoxifen maintenance for two years. This case exemplified second primary vulvar melanoma following breast cancer and supported that radiotherapy might play a role in the onset of secondary cancer. This case report also emphasizes the onset of endometrial polyp induced by tamoxifen.


Assuntos
Neoplasias da Mama/terapia , Neoplasias do Endométrio/patologia , Melanoma/patologia , Segunda Neoplasia Primária/patologia , Pólipos/patologia , Neoplasias Vulvares/patologia , Neoplasias do Endométrio/etiologia , Feminino , Humanos , Melanoma/etiologia , Pessoa de Meia-Idade , Segunda Neoplasia Primária/etiologia , Pólipos/etiologia , Radioterapia/efeitos adversos , Tamoxifeno/efeitos adversos , Neoplasias Vulvares/etiologia
8.
Clin Oral Investig ; 17(3): 887-96, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22699659

RESUMO

OBJECTIVES: Botulinum toxin A (Botox) is increasingly used for treatment of muscle hyperfunction. For a better understanding of the possible morphologic and chewing changes in patients induced by a therapy with Botox, muscle fiber and myosin heavy chain (MyHC) mRNA alterations were examined in this animal study. MATERIALS AND METHODS: The investigation was carried out on 14-week-old pigs (seven treated animals, eight controls; calculated animal size with a power of 0.5). To initialise the total immobilisation of the right masseter, the Botox injection was distributed into ten areas. After a 56-day period, muscle tissue was taken from the left and right side of the masseter (three regions), temporal (two regions), medial pterygoid and geniohyoid muscles using a standardized method. The muscle fiber cross sections were examined immunohistochemically. Fiber staining was accomplished with antibodies to specific MyHC isoforms. The MyHC mRNA changes were analysed using real-time RT-PCR. RESULTS: Muscles adapt to such stress by changing fiber types and MyHC mRNA content. Paralysed masseters display atrophic changes while other masticatory muscles show hypertrophic changes. The results indicated that the typical distributions of type IIa und IIb fiber types in masticatory muscles were increased in the masseter muscles due to Botox application. On the other hand, the masseters without Botox in the treated group showed a significant increase of type I MyHC. CONCLUSIONS: Application of Botox may lead to uncontrolled structural changes in affected and unaffected muscles. CLINICAL RELEVANCE: Treatment of muscle hypertrophy with Botox may cause muscle imbalance.


Assuntos
Toxinas Botulínicas Tipo A/farmacologia , Paralisia Facial/tratamento farmacológico , Músculo Masseter/efeitos dos fármacos , Músculos da Mastigação/patologia , Cadeias Pesadas de Miosina/genética , Miosinas de Músculo Esquelético/genética , Animais , Toxinas Botulínicas Tipo A/uso terapêutico , Hipertrofia , Músculos da Mastigação/química , Músculos da Mastigação/efeitos dos fármacos , Denervação Muscular , Atrofia Muscular/tratamento farmacológico , Atrofia Muscular/patologia , Cadeias Pesadas de Miosina/efeitos dos fármacos , RNA Mensageiro/análise , Reação em Cadeia da Polimerase em Tempo Real , Suínos
9.
Front Oncol ; 13: 1292635, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38074643

RESUMO

Introduction: Many well-known risk factors for breast cancer are associated with dysbiosis (an aberrant microbiome). However, how bacterial products modulate cancer are poorly understood. In this study, we investigated the effect of an exopolysaccharide (EPS) produced by the commensal bacterium Bacillus subtilis on breast cancer phenotypes. Although B. subtilis is commonly included in probiotic preparations and its EPS protects against inflammatory diseases, it was virtually unknown whether B. subtilis-derived EPS affects cancer. Methods: This work investigated effects of EPS on phenotypes of breast cancer cells as a cancer model. The phenotypes included proliferation, mammosphere formation, cell migration, and tumor growth in two immune compromised mouse models. RNA sequencing was performed on RNA from four breast cancer cells treated with PBS or EPS. IKKß or STAT1 signaling was assessed using pharmacologic or RNAi-mediated knock down approaches. Results: Short-term treatment with EPS inhibited proliferation of certain breast cancer cells (T47D, MDA-MB-468, HCC1428, MDA-MB-453) while having little effect on others (MCF-7, MDA-MB-231, BT549, ZR-75-30). EPS induced G1/G0 cell cycle arrest of T47D cells while increasing apoptosis of MDA-MB-468 cells. EPS also enhanced aggressive phenotypes in T47D cells including cell migration and cancer stem cell survival. Long-term treatment with EPS (months) led to resistance in vitro and promoted tumor growth in immunocompromised mice. RNA-sequence analysis showed that EPS increased expression of pro-inflammatory pathways including STAT1 and NF-κB. IKKß and/or STAT1 signaling was necessary for EPS to modulate phenotypes of EPS sensitive breast cancer cells. Discussion: These results demonstrate a multifaceted role for an EPS molecule secreted by the probiotic bacterium B. subtilis on breast cancer cell phenotypes. These results warrant future studies in immune competent mice and different cancer models to fully understand potential benefits and/or side effects of long-term use of probiotics.

10.
RSC Adv ; 12(17): 10198-10203, 2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-36200125

RESUMO

A simple, new, green, and sensitive approach was established and validated for assay of the recently approved antineoplastic medication; darolutamide (DAR) in its authentic form, pharmaceutical formulation, and biological fluids fluorimetrically. This experiment relied on the native fluorescence of the cited drug and detects the ideal solvent utilized throughout the approach. The proposed approach was validated regarding linearity, accuracy, and precision. The calibration graph showed linearity over the range of 0.1-2.0 µg mL-1. The limit of detection and quantitation (LOD and LOQ) were 0.032 µg mL-1 and 0.09 µg mL-1, respectively. Because of the approach's high sensitivity, it was decided to spike the mentioned drug in plasma and urine samples. At last, checking for content uniformity was performed regarding the United States Pharmacopoeia (USP) by adjusting the proposed approach.

11.
Cureus ; 14(1): e21350, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35198267

RESUMO

Background After the emergence of the novel coronavirus disease pandemic, Saudi Arabia implemented lockdown restrictions to counter this infection and prevent its spread. There have been a lot of challenges to the majority of people, especially diabetic patients, which might result in an increased risk of developing complications and significant lifestyle changes, including physical inactivity, unhealthy diet, and psychological distress. Objective This study aims to assess the impact of coronavirus disease lockdown on children with type 1 diabetes (T1D) mellitus in Al-Khobar, Saudi Arabia. Methods This is a questionnaire-based cross-sectional study which was conducted in pediatric patients, aged ≤18 years old, with type I diabetes, who were attending the endocrine clinic at the King Fahd Hospital of the University (KFHU) in Al-Khobar, Saudi Arabia. A total of 250 patients were identified from the hospital databases, a total of 164 patients were included in the study, and one of the parents/guardians was interviewed through mobile phone after taking their consent. Results The medication compliance during the lockdown has significantly increased as the percentage of children who did not miss any dose of medications increased to 92.7% in comparison to 70.7% before the lockdown (P=0.000). Also, diabetic ketoacidosis (DKA)-related intensive care unit admission had significantly decreased during the lockdown (P=0.001). Regarding the number of consumed meals, it increased from 53.7% up to 68.3% before and during the lockdown period, respectively (P=0.005). In addition, there was no significant change in children's psychological health during the lockdown period (p= 0.123). Conclusion The study indicates that there was an increase in compliance to medications, a significant decrease in intensive care unit and emergency department admission due to hypo/hyperglycemia during the lockdown period. Medical practitioners are encouraged to educate diabetic patients regarding the importance of self-blood glucose monitoring, healthy lifestyle, psychological wellbeing, and regular follow-up through virtual clinics.

12.
J Neurol Sci ; 427: 117506, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34087568

RESUMO

Epilepsy surgery is recommended in selected patients with Tuberous Sclerosis Complex (TSC). However, reports on predictive factors of seizure outcome are variable. Here we report on seizure and cognitive outcome of 35 TSC patients who received surgery for refractory epilepsy in 7 Italian centers over a period of 22 years (1997-2019). The rate of seizure-free individuals at last follow-up (mean 7.5 years, range 1-21 years) was 51%. Patients with longer follow-up (≥10 years) had a lower rate of Engel I outcome (11.1%) than those who received surgery in the last 10 years (65.4%, p = 0.003). Factors associated with Engel II, III, IV outcome in our cohort included: high number of cortical tubers (≥5); presence of subependymal nodules (SENs); seizure onset before age 1 year; and multifocal interictal epileptic discharges (IEDs) on electroencephalogram (EEG). A subset of patients evaluated with Vineland Adaptive Behaviour Scales (VABS) showed developmental gains, in line with their developmental trajectories, but no improvement in standard scores after surgery was noted. Our study demonstrates that the rates of successful seizure outcome of epilepsy surgery in TSC have improved in the last 10 years. More than half of the patients achieved seizure freedom, and a high proportion of affected individuals experienced a reduction in seizure burden and in antiseizure medications. A comprehensive assessment after surgery should be performed in TSC patients to evaluate the overall neurodevelopmental outcome, as measures that are based only on seizure control do not adequately identify the benefits of surgery on global functioning in these patients.


Assuntos
Epilepsia , Esclerose Tuberosa , Eletroencefalografia , Epilepsia/etiologia , Epilepsia/cirurgia , Humanos , Lactente , Estudos Retrospectivos , Convulsões/epidemiologia , Convulsões/etiologia , Convulsões/cirurgia , Resultado do Tratamento , Esclerose Tuberosa/complicações , Esclerose Tuberosa/cirurgia
13.
Brain ; 130(Pt 2): 561-73, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17124189

RESUMO

Of the cases with nocturnal frontal lobe epilepsy (NFLE) approximately 30% are refractory to antiepileptic medication, with several patients suffering from the effects of both ongoing seizures and disrupted sleep. From a consecutive series of 522 patients operated on for drug-resistant focal epilepsy, 21 cases (4%), whose frontal lobe seizures occurred almost exclusively (>90%) during sleep, were selected. All patients underwent a comprehensive pre-surgical evaluation, which included history, interictal EEG, scalp video-EEG monitoring, high-resolution MRI and, when indicated, invasive recording by stereo-EEG (SEEG). There were 11 males and 10 females, whose mean age at seizure onset was 6.2 years, mean age at surgery was 24.7 years and seizure frequency ranged from <20/month to >300/month. Nine patients reported excessive daytime sleepiness (EDS). Prevalent ictal clinical signs were represented by asymmetric posturing (6 cases), hyperkinetic automatisms (10 cases), combined tonic posturing and hyperkinetic automatisms (4 cases) and mimetic automatisms (1 case). All patients reported some kind of subjective manifestations. Interictal and ictal EEG provided lateralizing or localizing information in most patients. MRI was unrevealing in 10 cases and it showed a focal anatomical abnormality in one frontal lobe in 11 cases. Eighteen patients underwent a SEEG evaluation to better define the epileptogenic zone (EZ). All patients received a microsurgical resection in one frontal lobe, tailored according to pre-surgical evaluations. Two patients were operated on twice owing to poor results after the first resection. Histology demonstrated a Taylor-type focal cortical dysplasia (FCD) in 16 patients and an architectural FCD in 4. In one case no histological change was found. After a post-operative follow-up of at least 12 months (mean 42.5 months) all the 16 patients with a Taylor's FCD were in Engel's Class Ia and the other 5 patients were in Engel's Classes II or III. After 6 months post-surgery EDS had disappeared in the 9 patients who presented this complaint pre-operatively. It is concluded that patients with drug-resistant, disabling sleep-related seizures of frontal lobe origin should be considered for resective surgery, which may provide excellent results both on seizures and on epilepsy-related sleep disturbances. An accurate pre-surgical evaluation, which often requires invasive EEG recording, is mandatory to define the EZ. Further investigation is needed to explain the possible causal relationships between FCD, particularly Taylor-type, and sleep-related seizures, as observed in this cohort of NFLE patients.


Assuntos
Epilepsia do Lobo Frontal/cirurgia , Sono , Adolescente , Adulto , Anticonvulsivantes/uso terapêutico , Mapeamento Encefálico/métodos , Criança , Ritmo Circadiano , Resistência a Medicamentos , Eletroencefalografia/métodos , Epilepsia do Lobo Frontal/tratamento farmacológico , Epilepsia do Lobo Frontal/patologia , Epilepsia do Lobo Frontal/fisiopatologia , Feminino , Seguimentos , Lobo Frontal/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Microcirurgia/métodos , Estudos Retrospectivos , Resultado do Tratamento , Gravação em Vídeo
14.
Childs Nerv Syst ; 24(12): 1437-45, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18704447

RESUMO

AIM: The aim of the study was to evaluate the surgical treatment of epilepsy and detection of possible early surgery predictive elements in patients with tuberous sclerosis complex (TSC). MATERIALS AND METHODS: Forty-two TSC patients with epilepsy were selected and divided into two main groups: definite and fruste forms. Definite forms were divided into different groups: patients with pharmacologically controlled epilepsy, patients with pharmacoresistant epilepsy excluded from surgery after an extensive presurgical assessment, and patients with a pharmacoresistant epilepsy who underwent surgery. We compared the definite TSC groups to identify elements that predict surgical candidacy. Second, we compared all operated patients to assess surgical outcome. CONCLUSION: We found several factors that could predict a surgical intervention even if identification of patients with refractory epilepsy who can benefit from surgery is an evolving process. Also, several positive factors for good surgical outcome were identified. Patients with the fruste form had excellent surgical outcome.


Assuntos
Epilepsia/cirurgia , Esclerose Tuberosa/complicações , Adolescente , Adulto , Criança , Pré-Escolar , Epilepsia/complicações , Epilepsia/tratamento farmacológico , Feminino , Humanos , Masculino , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Adulto Jovem
15.
Int J Oral Maxillofac Surg ; 37(1): 54-9, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17983729

RESUMO

Various studies have shown type I collagen (coll) to increase bone-implant contact (BIC) compared to uncoated implants. The aim of this animal study was to test whether the integration of chondroitin sulphate (CS) and the growth factor rhBMP-4 into a collagenous coating could further increase the measured BIC compared to collagen coated implants alone. The experimental implants had two recesses along the length axis. 120 implants with the surface modifications: coll, coll/CS, coll/CS/rhBMP-4 were inserted into the mandible of 20 minipigs. Six months after implantation, BIC was measured histomorphometrically on the surface and within the recesses. Due to the specific animal model and strict criteria in placement, 39.2 % of the implants were considered as failure and not included in the analysis. Of the successfully gained 73 implants, the highest percentage of BIC was obtained for coll/CS (40%), followed by coll (30%) and coll/CS/rhBMP-4 (27%), P=0.013. BIC within the recesses was highest for coll/CS (51%), followed by coll (43%) and coll/CS/rhBMP-4 (34%), P=0.025. The result suggests that the inclusion of CS slightly increases the BIC compared to collagen coated implants. The further inclusion of a low amount rhBMP-4 had a detrimental effect on bone formation compared to coll/CS, P<0.05.


Assuntos
Proteínas Morfogenéticas Ósseas/farmacologia , Sulfatos de Condroitina/farmacologia , Implantação Dentária Endóssea/métodos , Implantes Dentários , Osseointegração/efeitos dos fármacos , Animais , Proteína Morfogenética Óssea 4 , Bovinos , Materiais Revestidos Biocompatíveis/farmacologia , Colágeno/farmacologia , Propriedades de Superfície , Suínos , Porco Miniatura
16.
Oncogene ; 25(3): 448-62, 2006 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-16170350

RESUMO

Hepatitis C virus (HCV) core has a pleiotropic effect on various promoters. In this study, we found that the expression of nucleolar phosphoprotein B23 was enhanced in HCV core-expressing cells and, moreover, HCV core interacts directly with the C-terminal end of B23. Using sucrose gradient centrifugation analysis and immunoprecipitation assays, HCV core was found in a large complex containing B23 and its interacting partner transcription factor YY1. Both B23 and HCV core associated with YY1 in the central GA/GK-rich and C-terminal zinc finger domain. These physical interactions between core, B23, and YY1 led to ternary complex formation that was bound to the YY1 response element. In a transient cotransfection experiment, relief of the trans-suppression activity of YY1 on the YY1-response element-driven reporter by core and B23 was found. This is also true when examining the effects of these three constructs on the B23 promoter-driven reporter. Additionally, chromatin immunoprecipitation assays indicated that a transcriptional activation complex consisting of core, together with B23, p300, and YY1, was recruited to the YY1 response element of B23 promoter, and this probably occurred through complex formation between core and these three cellular transcription regulators. This is different from the situation in the absence of core, where YY1 and histone deacetylase 1, but not B23 and p300, were associated on the YY1 element as the transcription repression complex. Together, our results indicate that HCV core can recruit B23 and p300 to relieve the repression effect of YY1 on B23 promoter activity, a property that requires the intrinsic histone acetyltransferase activity of p300. Thus, because these three core-associated cellular transcription regulators have a multitude of cellular interacting proteins and are involved in a versatility of cellular processes, the complex formation described here may partially account for the pleiotropic effects of core protein on gene expression and cellular function in HCV-infected cells.


Assuntos
Regulação da Expressão Gênica/fisiologia , Hepacivirus/fisiologia , Proteínas Nucleares/metabolismo , Proteínas do Core Viral/fisiologia , Fator de Transcrição YY1/fisiologia , Fatores de Transcrição de p300-CBP/metabolismo , Linhagem Celular , Humanos , Imunoprecipitação , Microscopia Confocal , Proteínas Nucleares/genética , Nucleofosmina , Regiões Promotoras Genéticas
17.
Br J Oral Maxillofac Surg ; 45(6): 447-50, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17218041

RESUMO

We compared the healing and reaction in the mandibles of 11 sheep of a conventional bioresorbable screw osteosynthesis with the newly developed ultrasound-activated pin osteosynthesis. The thermal stress caused by insertion of the ultrasound-aided pins leads to no cellular reaction around the pin. There is neither clinical nor histological evidence of any initial inflammation that could have been induced by the insertion. Adequate attachment of fibrous tissue to the pin head and the absence of any inflammation are important preconditions for the introduction of this new method of osteosynthesis into clinical practice. Further advantageous characteristics are easy intraoperative handling and a reduction in operating time, because cutting the thread is not required. There must be sufficient interlinkage of the polymer and the trabecular structures to ensure stability.


Assuntos
Implantes Absorvíveis , Pinos Ortopédicos , Parafusos Ósseos , Implantação Dentária Endóssea/métodos , Fixação Interna de Fraturas/instrumentação , Ultrassom , Animais , Placas Ósseas , Fraturas Ósseas/cirurgia , Temperatura Alta , Mandíbula/cirurgia , Poliésteres , Carneiro Doméstico , Soldagem
18.
Br J Oral Maxillofac Surg ; 45(6): 451-6, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17275145

RESUMO

We compared a conventional resorbable screw osteosynthesis with a resorbable, ultrasound-activated pin osteosynthesis, and studied mechanical load capacity and operative handling. This new form of osteosynthesis aims to reduce operation times, and to avoid torque loads and screw fractures to achieve stability. A sheep craniotomy model simulated an operation for dysmorphia on an infant skull. Two rectangular craniotomies of equal size were created in 13 lamb skulls, and each refixed by different means: the first by mesh and 20 screws, and the second by mesh with 20 pins inserted with ultrasound activation. All osteosynthesis material consisted of resorbable amorphous poly-(d,l)-lactide (PDLLA) (Resorb-X, KLS Martin, Tuttlingen, Germany). The insertion time was recorded. The animals were killed at different times, and areas of the healing skull including the plates and pins or screws were removed and divided into sections, which were then tested. In total 74 pin-fixed and 77 screw-fixed samples were obtained. Bending and tensile tests were used to simulate different forms of loading. The time required for the insertion of pins was significantly shorter than for screws. The mechanical tests showed differences in the stability of the bond between the osteosynthesis plate and bone that depended on the osteosynthesis system and the length of time it was in the animal. The pin osteosynthesis gave a stable mechanical load capacity, which was significantly different from that of screw osteosynthesis. Advantages of ultrasound-assisted, resorbable, pin osteosynthesis, include optimum operative handling, reduced insertion time, avoidance of fractures of the fixation elements and higher three-dimensional load capacity.


Assuntos
Implantes Absorvíveis , Pinos Ortopédicos , Parafusos Ósseos , Craniossinostoses/cirurgia , Craniotomia/instrumentação , Implantação Dentária Endóssea/métodos , Ultrassom , Animais , Fenômenos Biomecânicos , Placas Ósseas , Modelos Animais de Doenças , Feminino , Temperatura Alta , Modelos Lineares , Masculino , Teste de Materiais , Maleabilidade , Poliésteres , Carneiro Doméstico , Crânio/cirurgia
19.
Brain ; 128(Pt 2): 321-37, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15618282

RESUMO

We present the results of a retrospective study on 10 patients operated on for intractable epilepsy associated with nodular heterotopia as identified by high resolution MRI. Seven patients had unilateral heterotopia, one patient had symmetric bilateral heterotopia and two patients had asymmetric bilateral heterotopia. By stereo-electroencephalogram (SEEG) (nine patients) interictal activity within nodules was similar in all cases, and ictal activity never started from nodules alone but from the overlying cortex or simultaneously in nodules and cortex. Excellent outcomes (Engel class Ia, 1987) were achieved in the seven patients with unilateral heterotopia, showing that surgery can be highly beneficial in such cases when the epileptogenic zone is carefully located prior to surgery by MRI and particularly SEEG. For the bilateral cases surgical outcomes were Engel IIa (one patient) or Engel IIIa (two patients). Histological/immunohistochemical studies of resected specimens showed that all nodules had similar microscopic organization, even though their extent and location varied markedly. The overlying cortex was dysplastic in nine patients, but of normal thickness. We suggest that nodule formation may be the result of a dual mechanism: (i) failure of a stop signal in the germinal periventricular region leading to cell overproduction; and (ii) early transformation of radial glial cells into astrocytes resulting in defective neuronal migration. The intrinsic interictal epileptiform activity of nodules may be due to an impaired intranodular GABAergic system.


Assuntos
Encefalopatias/cirurgia , Córtex Cerebral , Coristoma/cirurgia , Epilepsia/cirurgia , Adulto , Encefalopatias/complicações , Encefalopatias/patologia , Encefalopatias/fisiopatologia , Córtex Cerebral/patologia , Coristoma/complicações , Coristoma/patologia , Coristoma/fisiopatologia , Eletroencefalografia , Epilepsia/etiologia , Epilepsia/patologia , Epilepsia/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estudos Retrospectivos , Resultado do Tratamento
20.
Technol Health Care ; 14(4-5): 403-9, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17065761

RESUMO

Conventional osteosynthesis of proximal femur fractures is still affected by serious complication rates between 4-18%, even though advanced implant modifications and surgical techniques are common practice. In terms of increasing age and co-morbidity of patients this complication ratio is expected to increase even further in the immediate future. One major reason for implant failure is the decreasing stability potential of the implant due to a loss in mechanical properties of cancellous bone. Therefore, efforts in new intramedulary techniques specifically focus on the load bearing characteristics of the implant by developing new geometries to improve the implant-tissue interface. This investigation discusses first clinical results of the trochanteric fixation nail TFN (145 patients) and a biomechanical analysis of the blade/femur head interaction under different static loading conditions. The TFN shows promising performance in first clinical results. In the clinical study the overall complication rate was significantly lower compared to other similar osteosynthesis. For the investigation of the biomechanical stability of the helical TFN blade the following experiments were performed: Analysis of the axial load required for insertion of the blade by free rotation; measurement of the corresponding rotation angle for total insertion (32 mm) (n = 8); pull-out forces with suppressed rotation (n = 4); loads for rotational overwinding of the implant in the fully inserted condition (n = 4). All investigations were performed on human femoral heads. The bone mineral densities of the specimens were detected by QCT-scans. Prior to cadaveric testing the experimental set-up was validated (n = 8) by the use of synthetic foam blocks (Sawbone).


Assuntos
Pinos Ortopédicos , Fraturas do Colo Femoral/cirurgia , Fixação Interna de Fraturas/instrumentação , Fraturas do Quadril/cirurgia , Resultado do Tratamento , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Densidade Óssea , Estudos de Viabilidade , Feminino , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas/métodos , Prótese de Quadril , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Mecânico , Suporte de Carga
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