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1.
Curr Issues Mol Biol ; 46(1): 527-541, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38248336

RESUMO

Cancer stands out as a major global public health concern and a significant impediment to increasing life expectancy worldwide. Natural bioactives derived from plants are renowned for their efficacy in treating various types of cancer. Andrographis paniculata (Burm.f.) is a well-known plant traditionally employed in diverse medical systems across the globe. The 2-AEH2P monophosphoester, a molecule intricately involved in phospholipid turnover, demonstrates antiproliferative effects across a broad spectrum of cancer types. This study aims to assess the antitumor, antiproliferative, and pharmacological effects of andrographolide at different concentrations, both individually and in conjunction with 2-aminoethyl dihydrogen phosphate. The cytotoxicity of the treatments was evaluated using the colorimetric MTT method, cell cycle phases, mitochondrial electrical potential, and markers expression via flow cytometry, while the pharmacological effects were assessed using SynergyFinder software 3.0. Treatments with A. paniculata, isolated at concentrations of 10%, 30%, and 50% of andrographolide, induced cell death in tumor cells, resulting in a reduction in mitochondrial electrical potential and alterations in cell cycle phases, particularly a decrease in the population of MDA MB-231 cells in the G0/G1 phase. The combination treatments exhibited significant cytotoxicity toward tumor cells, with minimal toxicity observed in normal fibroblast cells FN1. This led to a reduction in mitochondrial electrical potential and cell cycle arrest in the S phase for MDA MB-231 cells. Across all concentrations, the combined treatments demonstrated a synergistic pharmacological effect, underscoring the efficacy of the association. There was a change in the markers involved in cell death, such as p53, caspase 3, Bcl-2, and cytochrome c, suggesting the induction of regulated cell death. Markers associated with progression and proliferation, such as cyclin D1 and p21, corroborate the findings for cytotoxicity and cell cycle arrest.

2.
Neurosurg Rev ; 47(1): 7, 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38063935

RESUMO

Parkinson's disease (PD) is characterized by cardinal motor signs: 4-6 Hz resting tremor, rigidity, and bradykinesia. In addition, 3-18% of PD patients have camptocormia, an abnormal forward flexion of the thoracolumbar spine, which may have a negative impact on patients' quality of life. Different possible treatments have been suggested for such a condition, but no one is resolutive. This study aims to define the possible impact of DBS, with selective targeting on the dorsal-lateral region of the STN, on the sagittal balance of patients affected by PD. Among all patients that have undergone DBS procedures in our institution, we selected eight subjects, four females and four males, with selective targeting on the dorsal-lateral region of the subthalamic nucleus (STN) because of camptocormia and other severe postural changes. Radiological assessments of spinal balance parameters before surgery and at 6 and 12 months postoperatively were carried out. Comparison of preoperative and postoperative spine X-ray data showed a statistically significant improvement in dorsal kyphosis angle (D-Cobb) 12 months after the operation. Deep brain stimulation with selective targeting of the dorsal lateral part of the STN may induce changes of the posture in patients with Parkinson's disease 12 months after the operation, which appears to improve in this small sample size, but larger observational and controlled trials would be required to confirm this observation.


Assuntos
Estimulação Encefálica Profunda , Doença de Parkinson , Curvaturas da Coluna Vertebral , Masculino , Feminino , Humanos , Doença de Parkinson/cirurgia , Estimulação Encefálica Profunda/métodos , Qualidade de Vida , Curvaturas da Coluna Vertebral/cirurgia
3.
Medicina (Kaunas) ; 59(3)2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36984580

RESUMO

Background and Objectives: Stress urinary incontinence (SUI) negatively affects women's quality of life, including sexual function. The aim of the current study was to evaluate the effect of polydimethylsiloxane (Macroplastique®) on sexual function in women of fertile age affected by SUI. Materials and Methods: Single-center prospective study. Sexually active women of fertile age with symptoms of pure SUI, which were urodynamically proven, were submitted to intraurethral Macroplastique® injection. At 6-months follow-up, their sexual function was evaluated with Female Sexual Function Index (FSFI), while the SUI cure rate was objectively assessed through a negative stress test and subjectively by a Patient Global Impression of Improvement (PGI-I) score < 3. The difference of coital incontinence prevalence was assessed between the baseline and the 6-month follow-up. Peri- and postoperative complications of Macroplastique® injection were recorded and classified according to the Clavien-Dindo system. Results: Twenty-one women fulfilled inclusion criteria and were submitted to Macroplastique® procedure. The concerning sexual function, desire, satisfaction, and overall FSFI score significantly improved. Since other domains were less impaired at the baseline, we could not assess significant improvement for all of them. We observed a complete regression of coital incontinence (0/21, 0%) in comparison with the baseline (5/21, 23.8%; p = 0.04). The objective SUI cure rate was 76% (16/21), while the subjective SUI cure rate was 80.9% (17/21). One woman developed de novo overactive bladder, and two women developed postoperative voiding dysfunction (self-solved in 24 h). Conclusions: The Macroplastique® urethral injection was demonstrated to be safe and effective in improving sexual function in sexually active women of fertile age affected by pure SUI, urodinamically proven at 6-months follow-up.


Assuntos
Incontinência Urinária por Estresse , Feminino , Humanos , Lactente , Incontinência Urinária por Estresse/cirurgia , Estudos Prospectivos , Qualidade de Vida , Dimetilpolisiloxanos/uso terapêutico , Resultado do Tratamento
4.
Childs Nerv Syst ; 38(7): 1281-1287, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35411438

RESUMO

INTRODUCTION: Optic pathway gliomas (OPGs) presenting with acute hydrocephalus represent a true neurosurgical and neurooncological challenge. Two main strategies are currently used: microsurgical removal of the tumor, restoring CSF pathways, and endoscopic biopsy associated with ventriculo-peritoneal shunt implantation. Since the availability of an ultrasonic aspirator handpiece, that can be used inside the working channel of a neuroendoscope, a different less invasive surgical strategy can be used. METHODS: Four pediatric patients were treated by endoscopic ultrasonic aspiration, in order to remove the upper pole of the tumor, obtaining tissue for diagnosis and restoring CSF pathways as initial treatment of OPG invading the third ventricle and causing hydrocephalus due to simultaneous blockage of both Monro foramina and of the Sylvian aqueduct. Surgical technique is described. Pre-operative and post-operative volumes were calculated on magnetic resonance imaging. RESULTS: In all cases, the surgical procedure was uneventful, the biopsy was diagnostic, and CSF pathways were restored. The amount of tumor removed ranged between 31 and 76%. All patients underwent oncological treatment of their tumors. One patient received V-P shunt only 1 year after endoscopic decompression due to tumor progression. CONCLUSION: Our preliminary results show that the use of endoscopic cavitron aspirator is safe and effective to obtain CSF flow restoration and tumor biopsy (for histological and molecular purposes), avoiding CSF shunt implant in the acute phase and offering the chance to obtain a consistent tumor debulking in a minimally invasive fashion. Neuroendoscopic approach together with modern target therapy offers the opportunity to avoid or delay major surgery.


Assuntos
Hidrocefalia , Neuroendoscopia , Glioma do Nervo Óptico , Transtornos Respiratórios , Criança , Descompressão Cirúrgica/efeitos adversos , Humanos , Hidrocefalia/cirurgia , Vértebras Lombares/cirurgia , Neuroendoscopia/métodos , Glioma do Nervo Óptico/complicações , Estudos Retrospectivos , Resultado do Tratamento , Ultrassom , Ventriculostomia/métodos
5.
Medicina (Kaunas) ; 58(4)2022 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-35454351

RESUMO

Background and Objectives: Insufficient connective urethra and bladder support related to childbirth and menopausal estrogen decrease leads to stress urinary incontinence (SUI). The aim of this review is to narratively report the efficacy and safety of new mini-invasive solutions for SUI treatment as laser energy devices, in particular, the microablative fractional carbon dioxide laser and the non-ablative Erbium-YAG laser. Materials and Methods: For this narrative review, a search of literature from PubMed and EMBASE was performed to evaluate the relevant studies and was limited to English language articles, published from January 2015 to February 2022. Results: A significant subjective improvement, assessed by the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-UI-SF) was reported at the 6-month follow up, with a cure rate ranged from 21% to 38%. A reduction of effect was evidenced between 6 and 24-36 months. Additionally, the 1-h pad weight test evidence a significant objective improvement at the 2-6-month follow up. Conclusions: SUI after vaginal laser therapy resulted statistically improved in almost all studies at short-term follow up, resulting a safe and feasible option in mild SUI. However, cure rates were low, longer-term data actually lacks and the high heterogeneity of methods limits the general recommendations. Larger RCTs evaluating long-term effects are required.


Assuntos
Terapia a Laser , Lasers de Estado Sólido , Terapia com Luz de Baixa Intensidade , Incontinência Urinária por Estresse , Feminino , Humanos , Lasers de Estado Sólido/uso terapêutico , Masculino , Resultado do Tratamento , Incontinência Urinária por Estresse/cirurgia
6.
Medicina (Kaunas) ; 58(6)2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35744038

RESUMO

To avoid complications related to mid-urethral slings (MUS), alternative procedures to treat stress urinary incontinence (SUI), such as urethral bulking agents (UBAs) have been adopted. The aim of this review is to narratively report the efficacy and safety of UBAs for SUI treatment. For this review, research from PubMed and EMBASE was performed to evaluate relevant studies that were undertaken from January 2012 to January 2022. Nineteen prospective studies were included. Several definitions of subjective and objective success were adopted. At a follow-up of <24 months, significant improvement was widely observed, even if with a heterogeneous rate of success between 32.7−90%, and a reinjection rate of 8.3−77.3%. Compared with other procedures, MUS resulted as significantly superior to UBAs but was balanced by a higher complication rate. Acute urinary retention, urinary tract infection and de novo urgency, and other complications, such as injection site rupture, urethral erosion and particle migration have been described after UBAs. SUI after UBAs treatment resulted in improvements in all studies and can be considered a safe and effective option to treat SUI. However, homogenous and longer-term data lack, limiting general recommendations. Thus, larger RCTs evaluating long-term effects are required.


Assuntos
Slings Suburetrais , Incontinência Urinária por Estresse , Feminino , Humanos , Estudos Prospectivos , Slings Suburetrais/efeitos adversos , Resultado do Tratamento , Uretra/cirurgia , Incontinência Urinária por Estresse/cirurgia
7.
Medicina (Kaunas) ; 58(10)2022 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-36295573

RESUMO

Background and objectives: Stress urinary incontinence (SUI) is the most common type of urinary incontinence, affecting approximately 46% of adult women. After failure of conservative treatment, the mid-urethral sling (MUS) is considered the most effective and safe surgical procedure for SUI. In 2012, Waltregny et al. introduced a new trans-obturator tension-free vaginal tape (TVT) procedure, named TVT-abbrevo (TVT-A). The aim of the present study is to evaluate the efficacy and safety of the TVT-A procedure in women with pure SUI at 5-year follow-up. Materials and Methods: All women who complained of pure SUI symptoms with concomitant urodynamic stress incontinence (USI) were prospectively enrolled and treated with the TVT-A procedure. Postoperative subjective outcome measures included: International Consultation on Incontinence Questionnaire-Short Form (ICI-Q SF), Patient Global Impression of Improvement (PGI-I) scale, and patient degree of satisfaction scale. A PGI-I score ≤ 2 and a patient-satisfaction score ≥8 were used to define subjective success. Objective success was defined as the absence of urine leakage during a cough stress test. Adverse events were collected according to the Clavien-Dindo classification during follow-up. Results: Univariable analysis was used to investigate outcomes. Fifty women who met the inclusion criteria underwent TVT-A implantation. At 5 years after TVT-A implantation, 38 out of 45 (84.4%) patients were subjectively cured (p for trend 0.05), and 40 out of 45 (88.9%) patients were objectively cured (p for trend 0.04). A significant trend of de novo OAB symptoms was reported (22.2% [10/45]) at the 5-year follow-up. No serious early or late complications such as urethral/bladder injury, persistent groin-thigh pain, and sexual dysfunction that required mesh removal were detected. The univariate analysis did not reveal any risk factors (i.e., age, body mass index (BMI), menopause, obstetric factors, and preoperative ICIQ- SF questionnaire) statistically associated with failure of the TVT-A procedure. Conclusions: In conclusion, the 5-year follow-up results of this study demonstrated that TVT-A is a safe and effective option for treatment of SUI with a very low rate of post-operative groin-thigh pain.


Assuntos
Slings Suburetrais , Incontinência Urinária por Estresse , Incontinência Urinária , Adulto , Humanos , Feminino , Incontinência Urinária por Estresse/cirurgia , Seguimentos , Resultado do Tratamento , Dor Pós-Operatória
8.
Metab Brain Dis ; 36(5): 1015-1027, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33620579

RESUMO

Maple syrup urine disease (MSUD) is a genetic disorder that leads the accumulation of branched-chain amino acids (BCAA) leucine (Leu), isoleucine, valine and metabolites. The symptomatology includes psychomotor delay and mental retardation. MSUD therapy comprises a lifelong protein strict diet with low BCAA levels and is well established that high concentrations of Leu and/or its ketoacid are associated with neurological symptoms. Recently, it was demonstrated that the phenylbutyrate (PBA) have the ability to decrease BCAA concentrations. This work aimed the development of lipid-based nanoparticles loaded with PBA, capable of targeting to the central nervous system in order to verify its action mechanisms on oxidative stress and cell death in brain of rats subjected to a MSUD chronic model. PBA-loaded nanoparticles treatment was effective in significantly decreasing BCAA concentration in plasma and Leu in the cerebral cortex of MSUD animals. Furthermore, PBA modulate the activity of catalase, superoxide dismutase, glutathione peroxidase and glutathione reductase enzymes, as well as preventing the oxidative damage to lipid membranes and proteins. PBA was also able to decrease the glial fibrillary acidic protein concentrations and partially decreased the reactive species production and caspase-3 activity in MSUD rats. Taken together, the data indicate that the PBA-loaded nanoparticles could be an efficient adjuvant in the MSUD therapy, protecting against oxidative brain damage and neuroinflammation.


Assuntos
Aminoácidos de Cadeia Ramificada/sangue , Córtex Cerebral/efeitos dos fármacos , Doença da Urina de Xarope de Bordo/metabolismo , Nanopartículas/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Fenilbutiratos/administração & dosagem , Animais , Catalase/metabolismo , Córtex Cerebral/metabolismo , Glutationa Peroxidase/metabolismo , Doença da Urina de Xarope de Bordo/sangue , Doença da Urina de Xarope de Bordo/induzido quimicamente , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo
9.
J Shoulder Elbow Surg ; 30(4): 763-771, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32763384

RESUMO

BACKGROUND: Multiple modifications of reverse total shoulder arthroplasty (RTSA) since the first Grammont design have developed to improve range of motion (ROM) and avoid notching. The effect of these changes in shoulder kinematics and the best compromise for ROM is still under debate. This computer simulation study evaluates the influence of humeral design, humeral neck-shaft angle (NSA), glenoid lateralization, and glenoid eccentricity on ROM of RTSA. METHODS: We created a 3-dimensional computer model from computed tomography scans of 13 patients with primary osteoarthritis simulating implantation of a standardized reverse shoulder arthroplasty. We analyzed the effect of 4 different variables on impingement-free ROM: humeral design (inlay vs. semi-inlay vs. onlay), humeral NSA (135° vs. 145° vs. 155°), glenoid lateralization, and glenoid eccentricity on ROM. RESULTS: The use of different humeral stem designs did not have a significant effect on total global ROM. Reducing NSA demonstrated a significant increase in adduction, and external and internal rotation in adduction, whereas a decrease in abduction and external rotation in abduction. Glenosphere lateralization was the most effective method for increasing total global ROM (P < .0001); however, extreme lateralization (+12 mm) did not show significant benefit compared with moderate lateralization (+4 mm). Glenosphere eccentricity increased only adduction and internal rotation in adduction. CONCLUSION: Only glenoid lateralization has a significant effect on increasing total global ROM in RTSA. The use of the semi-inlay 145° model combined with 4 mm lateralization and 2 mm inferior eccentricity represents the middle ground and the most universal approach in RTSA.


Assuntos
Artroplastia do Ombro , Simulação por Computador , Osteoartrite/diagnóstico por imagem , Articulação do Ombro , Prótese de Ombro , Cavidade Glenoide/diagnóstico por imagem , Cavidade Glenoide/cirurgia , Humanos , Úmero/diagnóstico por imagem , Úmero/cirurgia , Imageamento Tridimensional , Osteoartrite/cirurgia , Desenho de Prótese , Amplitude de Movimento Articular , Articulação do Ombro/diagnóstico por imagem , Articulação do Ombro/cirurgia , Tomografia Computadorizada por Raios X
10.
Acta Neurochir (Wien) ; 161(8): 1633-1646, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31175456

RESUMO

BACKGROUND AND OBJECTIVE: Management of selected spheno-orbital meningiomas via the endoscopic transorbital route has been reported. Surgical maneuverability in a narrow corridor as that offered by the orbit may be challenging. We investigate the additional use of an extra-orbital (EXO) path to be used in combination with the endo-orbital (EO) corridor. MATERIAL AND METHODS: Three human cadaveric heads (six orbits) were dissected at the Laboratory of Surgical Neuroanatomy at the University of Barcelona. The superior eyelid endoscopic transorbital approach was adopted, introducing surgical instruments via both corridors. Surgical freedom analysis was run to determine directionality of each corridor and to calculate the surgical maneuverability related to three anatomic targets: superior orbital fissure (SOF), foramen rotundum (FR), and foramen ovale (FO). We also reported of a 37-year-old woman with a spheno-orbital meningioma with hyperostosis of the lateral wall of the right orbit, treated with such combined endo-orbital and extra-orbital endoscopic approach. RESULTS: Combining both endo-orbital and extra-orbital corridors permitted a greater surgical freedom for all the targets compared with the surgical freedom of each corridor alone (EO + EXO to SOF: 3603.8 mm2 ± 2452.5 mm2; EO + EXO to FR: 1533.0 mm2 ± 892.2 mm2; EO + EXO to FO: 1193.9 mm2 ± 782.6 mm2). Analyzing the extra-orbital pathway, our results showed that the greatest surgical freedom was gained in the most medial portion of the considered area, namely the SOF (1180.5 mm2 ± 648.3 mm2). Regarding the surgical case, using both pathways, we gained enough maneuverability to nearly achieve total resection with no postoperative complications. CONCLUSION: An extra-orbital corridor may be useful to increase the instruments' maneuverability, during a pure endoscopic superior eyelid approach, and to reach the most medial portion of the surgical field from a lateral-to-medial trajectory. Further studies are needed to better define the proper indications for such strategy.


Assuntos
Endoscopia/métodos , Hiperostose/cirurgia , Neoplasias Meníngeas/cirurgia , Meningioma/cirurgia , Procedimentos Neurocirúrgicos/métodos , Órbita/cirurgia , Osso Esfenoide/cirurgia , Adulto , Endoscopia/efeitos adversos , Pálpebras/cirurgia , Feminino , Humanos , Hiperostose/complicações , Neoplasias Meníngeas/complicações , Meningioma/complicações , Procedimentos Neurocirúrgicos/efeitos adversos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle
11.
Metab Brain Dis ; 33(1): 333-342, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29260360

RESUMO

Several studies have examined neonatal diabetes, a rare disease characterized by hyperglycemia and low insulin levels that is usually diagnosed in the first 6 month of life. Recently, the effects of diabetes on the brain have received considerable attention. In addition, hyperglycemia may perturb brain function and might be associated with neuronal death in adult rats. However, few studies have investigated the damaging effects of neonatal hyperglycemia on the rat brain during central nervous system (CNS) development, particularly the mechanisms involved in the disease. Thus, in the present work, we investigated whether neonatal hyperglycemia induced by streptozotocin (STZ) promoted cell death and altered the levels of proteins involved in survival/death pathways in the rat brain. Cell death was assessed using FluoroJade C (FJC) staining and the expression of the p38 mitogen-activated protein kinase (p38), phosphorylated-c-Jun amino-terminal kinase (p-JNK), c-Jun amino-terminal kinase (JNK), protein kinase B (Akt), phosphorylated-protein kinase B (p-Akt), glycogen synthase kinase-3ß (Gsk3ß), B-cell lymphoma 2 (Bcl2) and Bcl2-associated X protein (Bax) protein were measured by Western blotting. The main results of this study showed that the metabolic alterations observed in diabetic rats (hyperglycemia and hypoinsulinemia) increased p38 expression and decreased p-Akt expression, suggesting that cell survival was altered and cell death was induced, which was confirmed by FJC staining. Therefore, the metabolic conditions observed during neonatal hyperglycemia may contribute to the harmful effect of diabetes on the CNS in a crucial phase of postnatal neuronal development.


Assuntos
Encéfalo/patologia , Morte Celular/fisiologia , Hiperglicemia/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Animais , Encéfalo/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Feminino , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Neurônios/metabolismo , Fosforilação , Ratos Wistar , Proteína X Associada a bcl-2/metabolismo
12.
Chem Soc Rev ; 44(4): 920-42, 2015 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-25522058

RESUMO

Constructing electronic circuits containing singly wired molecules is at the frontier of electrical device miniaturisation. When a molecule is wired between a pair of electrodes, the two points of contact are determined by the chemical anchoring groups, located at the ends of the molecule. At this point, when a bias is applied, electrons are channelled from a metallic environment through an extremely narrow constriction, essentially a single atom, into the molecule. The fact that this is such an abrupt change in the electron pathway makes the nature of the chemical anchoring groups critically important regarding the propagation of electrons from the electrode across the molecule. A delicate interplay of phenomena can occur when a molecule binds to the electrodes, which can produce profound differences in conductance properties depending on the anchoring group. This makes answering the question "what is the best anchoring group for single molecule studies" far from straight forward. In this review, we firstly take a look at techniques developed to 'wire-up' single molecules, as understanding their limitations is key when assessing a molecular wire's performance. We then analyse the various chemical anchoring groups, and discuss their merits and disadvantages. Finally we discuss some theoretical concepts of molecular junctions to understand how transport is affected by the nature of the chemical anchor group.

13.
J Am Chem Soc ; 137(6): 2318-27, 2015 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-25651069

RESUMO

Single molecule charge transport characteristics of buckminsterfullerene-capped symmetric fluorene-based dumbbell-type compound 1 were investigated by scanning tunneling microscopy break junction (STM-BJ), current sensing atomic force microscopy break junction (CS-AFM-BJ), and mechanically controlled break junction (MCBJ) techniques, under ambient conditions. We also show that compound 1 is able to form highly organized defect-free surface adlayers, allowing the molecules on the surface to be addressed specifically. Two distinct single molecule conductance states (called high G(H)(1) and low G(L)(1)) were observed, depending on the pressure exerted by the probe on the junction, thus allowing molecule 1 to function as a mechanically driven molecular switch. These two distinct conductance states were attributed to the electron tunneling through the buckminsterfullerene anchoring group and fully extended molecule 1, respectively. The assignment of conductance features to these configurations was further confirmed by control experiments with asymmetrically designed buckminsterfullerene derivative 2 as well as pristine buckminsterfullerene 3, both lacking the G(L) feature.

14.
Opt Express ; 23(4): 4114-24, 2015 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-25836449

RESUMO

Developing versatile joining techniques to weld transparent materials on a micrometer scale is of great importance in a growing number of applications, especially for the fabrication and assembly of biomedical devices. In this paper, we report on fs-laser microwelding of two transparent layers of polymethyl methacrylate (PMMA) based on nonlinear absorption and localized heat accumulation at high repetition rates. A fiber CPA laser system was used delivering 650-fs pulses at 1030 nm with repetition rates in the MHz regime. The laser-induced modifications produced by the focused beam into the bulk PMMA were firstly investigated, trying to find a suitable set of process parameters generating continuous and localized melting. Results have been evaluated based on existing heat accumulation models. Then, we have successfully laser welded two 1-mm-thick PMMA layers in a lap-joint configuration. Sealing of the sample was demonstrated through static and dynamic leakage tests. This fs-laser micro-welding process does not need any pre-processing of the samples or any intermediate absorbing layer. Furthermore, it offers several advantages compared to other joining techniques, because it prevents contamination and thermal distortion of the samples, thus being extremely interesting for application in direct laser fabrication of microfluidic devices.

15.
Mol Cell Biochem ; 403(1-2): 159-67, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25682169

RESUMO

Recently, the consequences of diabetes on the central nervous system (CNS) have received great attention. However, the mechanisms by which hyperglycemia affects the central nervous system remain poorly understood. In addition, recent studies have shown that hyperglycemia induces oxidative damage in the adult rat brain. In this regard, no study has assessed oxidative stress as a possible mechanism that affects the brain normal function in neonatal hyperglycemic rats. Thus, the present study aimed to investigate whether neonatal hyperglycemia elicits oxidative stress in the brain of neonate rats subjected to a streptozotocin-induced neonatal hyperglycemia model (5-day-old rats). The activities of glucose-6-phosphate-dehydrogenase (G6PD), 6-phosphogluconate-dehydrogenase (6-PGD), NADPH oxidase (Nox), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx), the production of superoxide anion, the thiobarbituric acid-reactive substances (TBA-RS), and the protein carbonyl content were measured. Neonatal hyperglycemic rats presented increased activities of G6PD, 6PGD, and Nox, which altogether may be responsible for the enhanced production of superoxide radical anion that was observed. The enhanced antioxidant enzyme activities (SOD, CAT, and GSHPx) that were observed in neonatal hyperglycemic rats, which may be caused by a rebound effect of oxidative stress, were not able to hinder the observed lipid peroxidation (TBA-RS) and protein damage in the brain. Consequently, these results suggest that oxidative stress could represent a mechanism that explains the harmful effects of neonatal hyperglycemia on the CNS.


Assuntos
Encéfalo/enzimologia , Encéfalo/patologia , Hiperglicemia/patologia , NADPH Oxidases/metabolismo , Estresse Oxidativo , Via de Pentose Fosfato , Animais , Animais Recém-Nascidos , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Carbonilação Proteica , Ratos Wistar , Superóxidos/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
16.
J Org Chem ; 79(11): 4871-7, 2014 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-24750127

RESUMO

Two C60 dumbbell molecules have been synthesized containing either cyclopropane or pyrrolidine rings connecting two fullerenes to a central fluorene core. A combination of spectroscopic techniques reveals that the cyclopropane dumbbell possesses better electronic communication between the fullerenes and the fluorene. This observation is underpinned by DFT transport calculations, which show that the cyclopropane dumbbell gives a higher calculated single-molecule conductance, a result of an energetically lower-lying LUMO level that extends deeper into the backbone. This strengthens the idea that cyclopropane behaves as a quasi-double bond.

17.
Cell Biochem Funct ; 32(8): 711-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25431174

RESUMO

There is increasing evidence suggesting that oxidative stress plays an important role in the development of many chronic and degenerative conditions such as diabetic encephalopathy and depression. Considering that diabetic rats and mice present higher depressive-like behaviour when submitted to the forced swimming test and that treatment with insulin and/or clonazepam is able to reverse the behavioural changes of the diabetic rats, the present work investigated the antioxidant status, specifically total antioxidant reactivity and antioxidant potential of insulin and clonazepam, as well as the effect of this drugs upon protein oxidative damage and reactive species formation in cortex, hippocampus and striatum from diabetic rats submitted to forced swimming test. It was verified that longer immobility time in diabetic rats and insulin plus clonazepam treatment reversed this depressive-like behaviour. Moreover, data obtained in this study allowed to demonstrate through different parameters such as protein carbonyl content, 2'7'-dichlorofluorescein oxidation, catalase, superoxide dismutase, glutathione peroxidase assay, total radical-trapping antioxidant potential and total antioxidant reactivity that there is oxidative stress in cortex, hippocampus and striatum from diabetic rats under depressive-like behaviour and highlight the insulin and/or clonazepam effect in these different brain areas, restoring antioxidant status and protein damage.


Assuntos
Anticonvulsivantes/uso terapêutico , Encefalopatias/complicações , Clonazepam/uso terapêutico , Depressão/tratamento farmacológico , Diabetes Mellitus Experimental/complicações , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Animais , Antioxidantes/metabolismo , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Depressão/etiologia , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
18.
Metab Brain Dis ; 29(3): 609-15, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24488205

RESUMO

Phenylketonuria (PKU) is a disorder caused by a deficiency in phenylalanine hydroxylase activity, which converts phenylalanine (Phe) to tyrosine, leading to hyperphenylalaninemia (HPA) with accumulation of Phe in tissues of patients. The neuropathophysiology mechanism of disease remains unknown. However, recently the involvement of oxidative stress with decreased glutathione levels in PKU has been reported. Intracellular glutathione (GSH) levels may be maintained by the antioxidant action of lipoic acid (LA). The aim of this study was to evaluate the activity of the enzymes involved in the metabolism and function of GSH, such as glutathione peroxidase (GSH-Px), glucose-6-phosphate dehydrogenase (G6PD), glutathione reductase (GR), glutamate-cysteine ligase (GCL), glutathione-S-transferase (GST) and GSH content in brain and liver of young rats subjected to a chemically induced model of HPA and the effect of LA for a week. In brain, the administration of Phe reduced the activity of the GSH-Px, GR and G6PD and LA prevented these effects totally or partially. GCL activity was increased by HPA and was not affect by LA antioxidant treatment. GST activity did not differ between groups. GSH content was increased by LA and decreased by HPA treatment in brain samples. Considering the liver, all parameters analyzed were increased in studied HPA animals and LA was able to hinder some effects except for the GCL, GST enzymes and GSH content. These results suggested that HPA model alter the metabolism of GSH in rat brain and liver, which may have an important role in the maintenance of GSH function in PKU although liver is not a directly affected organ in this disease. So, an antioxidant therapy with LA may be useful in the treatment of oxidative stress in HPA.


Assuntos
Encéfalo/enzimologia , Glutationa/metabolismo , Fígado/enzimologia , Fenilcetonúrias/enzimologia , Ácido Tióctico/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar
19.
Environ Pollut ; 348: 123816, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38508369

RESUMO

The increase of plastic production together with the incipient reuse/recycling system has resulted in massive discards into the environment. This has facilitated the formation of micro- and nanoplastics (MNPs) which poses major risk for environmental health. Although some studies have investigated the effects of pristine MNPs on reproductive health, the effects of weathered MNPs have been poorly investigated. Here we show in Caenorhabditis elegans that exposure to photoaged polystyrene nanoplastics (PSNP-UV) results in worse reproductive performance than pristine PSNP (i.e., embryonic/larval lethality plus a decrease in the brood size, accompanied by a high number of unfertilized eggs), besides it affects size and locomotion behavior. Those effects were potentially generated by reactive products formed during UV-irradiation, since we found higher levels of reactive oxygen species and increased expression of GST-4 in worms exposed to PSNP-UV. Those results are supported by physical-chemical characterization analyses which indicate significant formation of oxidative degradation products from PSNP under UV-C irradiation. Our study also demonstrates that PSNP accumulate predominantly in the gastrointestinal tract of C. elegans (with no accumulation in the gonads), being completely eliminated at 96 h post-exposure. We complemented the toxicological analysis of PSNP/PSNP-UV by showing that the activation of the stress response via DAF-16 is dependent of the nanoplastics accumulation. Our data suggest that exposure to the wild PSNP, i.e., polystyrene nanoplastics more similar to those actually found in the environment, results in more important reprotoxic effects. This is associated with the presence of degradation products formed during UV-C irradiation and their interaction with biological targets.


Assuntos
Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Poliestirenos/metabolismo , Microplásticos/toxicidade , Microplásticos/metabolismo , Estresse Oxidativo , Proteínas de Caenorhabditis elegans/metabolismo
20.
Small ; 9(22): 3812-22, 2013 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-23630169

RESUMO

A combined experimental and theoretical investigation is carried out into the electrical transport across a fullerene dumbbell one-molecule junction. The newly designed molecule comprises two C60 s connected to a fluorene backbone via cyclopropyl groups. It is wired between gold electrodes under ambient conditions by pressing the tip of a scanning tunnelling microscope (STM) onto one of the C60 groups. The STM allows us to identify a single molecule before the junction is formed through imaging, which means unambiguously that only one molecule is wired. Once lifted, the same molecule could be wired many times as it was strongly fixed to the tip, and a high conductance state close to 10(-2) G0 is found. The results also suggest that the relative conductance fluctuations are low as a result of the low mobility of the molecule. Theoretical analysis indicates that the molecule is connected directly to one electrode through the central fluorene, and that to bind it to the gold fully it has to be pushed through a layer of adsorbates naturally present in the experiment.

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