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1.
Mol Cell Biochem ; 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38427166

RESUMO

The Yes-associated protein (YAP) oncoprotein has been linked to both metastases and resistance to targeted therapy of lung cancer cells. We aimed to investigate the effect of YAP pharmacological inhibition, using YAP/TEA domain (TEAD) transcription factor interaction inhibitors in chemo-resistant lung cancer cells. YAP subcellular localization, as a readout for YAP activation, cell migration, and TEAD transcription factor functional transcriptional activity were investigated in cancer cell lines with up-regulated YAP, with and without YAP/TEAD interaction inhibitors. Parental (A549) and paclitaxel-resistant (A549R) cell transcriptomes were analyzed. The half-maximal inhibitory concentration (IC50) of paclitaxel or trametinib, which are Mitogen-Activated protein kinase and Erk Kinase (MEK) inhibitors, combined with a YAP/TEAD inhibitor (IV#6), was determined. A three-dimensional (3D) microfluidic culture device enabled us to study the effect of IV#6/paclitaxel combination on cancer cells isolated from fresh resected lung cancer samples. YAP activity was significantly higher in paclitaxel-resistant cell lines. The YAP/TEAD inhibitor induced a decreased YAP activity in A549, PC9, and H2052 cells, with reduced YAP nuclear staining. Wound healing assays upon YAP inhibition revealed impaired cell motility of lung cancer A549 and mesothelioma H2052 cells. Combining YAP pharmacological inhibition with trametinib in K-Ras mutated A549 cells recapitulated synthetic lethality, thereby sensitizing these cells to MEK inhibition. The YAP/TEAD inhibitor lowered the IC50 of paclitaxel in A549R cells. Differential transcriptomic analysis of parental and A549R cells revealed an increased YAP/TEAD transcriptomic signature in resistant cells, downregulated upon YAP inhibition. The YAP/TEAD inhibitor restored paclitaxel sensitivity of A549R cells cultured in a 3D microfluidic system, with lung cancer cells from a fresh tumor efficiently killed by YAP/TEAD inhibitor/paclitaxel doublet. Evidence of the YAP/TEAD transcriptional program's role in chemotherapy resistance paves the way for YAP therapeutic targeting.

2.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 147-154, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281311

RESUMO

Pain, bad taste, and impaired daily activity after implant therapy are common sequelae. Concentrated growth factors (CGF) are a platelet concentrate with a favourable effect on wound healing, but there is still no evidence regarding its potential benefits for reducing postoperative pain and symptoms. Therefore, aim of this prospective comparative study was to determine the effect of CGF on quality of life (QoL) of patients after implant therapy. Fifty-two consecutive patients with one missing mandibular molar were included in the study and alternatively assigned to two groups. Control group received standard implant treatment, and test group received CGF associated with implants. Standard periapical radiographs were taken before and after procedure. Post-operative care consisted of 0.2% chlorhexidine digluconate solution twice daily for 10 days. A QoL questionnaire (OHIP-14) for bad taste, pain and limitation in daily activities was filled and returned one week post-operatively. Daily pain was also assessed through Visual Analogue Scale (VAS) on a 1-100 scale. Parametric test (chi-square) was performed to compare the results of the questionnaire between the two groups using STATA statistical software. All patients correctly filled and returned the questionnaire. Significantly higher proportions of patients of test group reported no bad taste, pain, and limited activity, (24/26, 13/26, and 25/26, respectively) respect to control. Postoperative pain with VAS score was significantly lower in the test group on day 1, 2, and 3 as compared to control. CGF positively influenced QoL when associated with implant rehabilitation of mandibular molars, minimizing post-operative discomfort.


Assuntos
Dor Pós-Operatória , Qualidade de Vida , Estudos de Coortes , Humanos , Medição da Dor , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controle , Estudos Prospectivos
3.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 117-129, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281308

RESUMO

The aim of this retrospective case series was to evaluate the clinical and radiographic outcomes of the patients that underwent implant surgery with a modification of the sinus lift summers protocol. Forty healthy patients in need for oral rehabilitation with dental implants were included in this study. Inclusion criterion was the need for extraction of one compromised tooth due to persistent abscess/ periodontitis/cyst in the atrophic posterior maxilla region. The treatment consisted of two stage surgery for all patients. In the first stage, after tooth extraction, the sockets were preserved with allogenic bone graft and equine collagen membrane. After 4-5 months, 40 implants with a sandblasted surface, were inserted with osseodensification technique and a modification of the Summers sinus lift protocol for fracturing the sinus floor. The implant survival rate was the primary outcome. Intra- and postoperative complications were additional criteria for success. The mean follow-up from implant surgery was 28.0±7.3 (standard deviation) months (range 17.8-43.4 months). One implant was lost before the delivery of the prosthesis. The overall implant survival rate was 97.5%. The overall mean peri-implant marginal bone level change after 6 and 12 months of function was, respectively, 0.26±0.24 mm (95% CI: 0.19, 0.34 mm) and 0.71±0.36 mm (95% CI: 0.60, 0.82 mm). Marginal bone loss was statistically significant at both time frames respect to implant placement, and also the difference between 6 and 12 months was significant (p<0.001 in both cases). No biological nor mechanical complications were recorded throughout the observation period. As a conclusion, the technique presented in this cohort study can be an effective and safe alternative to standard maxillary sinus floor augmentation procedures and immediate implant insertion protocol, especially in cases of periodontitis and infected sites, which can represent a high risk for implant failure in patients with atrophic posterior maxilla.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Levantamento do Assoalho do Seio Maxilar , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/cirurgia , Animais , Estudos de Coortes , Seguimentos , Cavalos , Humanos , Próteses e Implantes , Estudos Retrospectivos , Resultado do Tratamento
4.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 107-115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281307

RESUMO

The objective of the research was to evaluate the location, size, variability, and morphologic features of mental foramen (MF) and the inferior alveolar nerve canal (IAN) on cone-beam CT. We evaluated the morphologic findings of mental foramen (MF) and inferior alveolar nerve (IAN) canal of 88 mandibular hemiarches of 65 Caucasian subjects (35 males, 30 females; age range 25-75 years) using cone beam CT. The most common horizontal position of MF was type 3 (53.4%), followed by type 4 (39.8%), type 1 (2.3%), type 2 (2.3%), and type 5 (2.3%). Regarding the vertical position, in 71.6% of cases (63/88) we found type 3 position, followed by type 2 (22.7%) and type 1 (5.7%). MF presented as oval in 51.1% and round in 42%, with double oval and triple foramens having been observed in 5.7% and 1.1% respectively. In 36.9% of cases, we found an anterior loop of the IAN. The mean depth of MF was 6.12±1.65mm; width and height were 3.7±0.83mm and 3.14±0.78mm. Width and height of the IAN distal to MF were 2.27±0.53mm and 2.74±0.51mm, while those of the incisive nerve canal mesial to MF were 1.37±0.44mm and 1.54±0.58mm, respectively. An increase in the width of MF was correlated to oval shape (r=0.45; P < 0.01), and there was a low but significant correlation (r=0.23; P < 0.05) between the round shape of MF and the size of the IAN. MF shape appears to be correlated to MF width and size of the IAN. The individual anatomical variability of this structure is a factor that must be considered when dealing with mandibular surgery.


Assuntos
Forame Mentual , Adulto , Idoso , Computadores , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Mandíbula/diagnóstico por imagem , Nervo Mandibular/diagnóstico por imagem , Pessoa de Meia-Idade
5.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 67-78, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281303

RESUMO

The objective of this study was to establish the significance of probiotic usage, both as a preventive as well as a therapeutic strategy for the management of periodontal disease. It also substantiates the existing studies of single/combined bacterial strain for exhibiting variable ecological impact on oral bacteria. Data sources included literature searches of PubMed (MEDLINE), Scopus, Embase, CENTRAL and Web of science databases for placebo controlled randomized clinical trials of SRP with orally administered probiotics in any form as an adjunct. Data extraction was conducted and information from the included studies was tabulated according to the study designs, form of drug delivery, main outcomes, and clinical parameters. Data collected were based on the focused question outlined for the present systematic review. The reviewers cross-checked all extracted data. CAL and PD were assessed as the primary outcome to compare the effectiveness of adjunctive probiotic therapy in addition to SRP. Fourteen clinical studies were included and demonstrated efficacy in reducing periodontal probing depth (PPD) and gaining clinical attachment level (CAL), between probiotics and SRP/placebo. Adjunctive probiotic therapy in addition to SRP leads to decrease in probing depth and clinical attachment gain in chronic periodontitis patients. However, further high-quality randomized clinical trials with microbiological outcomes are required to fortify the conclusion.


Assuntos
Periodontite Crônica , Probióticos , Periodontite Crônica/terapia , Terapia Combinada , Raspagem Dentária , Humanos , Probióticos/uso terapêutico , Aplainamento Radicular
6.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 97-105, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281306

RESUMO

Bibliometric Analysis researches and analyses the quantitative data derived from scientific publications through the empirical evidence of scientific activity generated by collaborating authors through the final product of their research: the scientific article. In scientific society, the concept of impact factor is probably the most widely used in bibliometric construction. To assess the scientometrics of three high-impact factor periodontal journals and identify the contribution of India in these most productive journals over three years (Jan 2018 - Dec 2020) and to know the most influential topics researched. A retrospective observational study was conducted for the Journal of Clinical Periodontology, Journal of Periodontology, and Journal of Periodontal Research. All issues of 2018, 2019, and 2020 were electronically and hand searched for the following parameters: Number of papers, affiliated organizations, and countries, topics reported, and contribution of Indian authors. The data were organized and analyzed with descriptive statistics using SPSS software (version 21.0). In total 469 articles were published by Journal of Periodontology, followed by 454 articles in Journal of Clinical Periodontology and 287 articles in Journal of Periodontal Research. In all the three journals, China had the maximum contributions, succeeded by USA. India has published maximum number of articles in the Journal of Periodontal Research. When analysed, although less as compared to the western counterparts, an increasing trend in the publications is seen in case of India.


Assuntos
Publicações Periódicas como Assunto , Bibliometria , China , Índia , Periodontia
7.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 79-88, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34281304

RESUMO

In the last decades, the presence of peri-implant diseases (PD) has increased. One of the therapies currently used is probiotics with Lactobacillus reuteri (LR). The aim of this article is to determinate, through a systematic review and meta-analysis, the clinical effectiveness of LR in the treatment of PD. We searched the literature until January 2021, in the biomedical databases: Pubmed, Embase, Scielo, Science Direct, Scopus, SIGLE, LILACS, Google Scholar and Cochrane Central Registry of Clinical Trials. The selection criteria of the studies were: randomized controlled clinical trials, without language and time restriction, reporting the clinical effects (depth to probing, plaque index and bleeding index) of the LR in the PD treatment. The risk of study bias was analyzed through the Cochrane tool for randomized studies using Review Manager software. The search strategy resulted in 6 articles of which four investigated peri-implantitis and three peri-implant mucositis. All studies reported that there was a difference in the depth of the probing in the treatment of PD, in favor of the group using LR, though not always achieving significance. The use of LR can be clinically effective in terms of pocket depth reduction in the treatment of PD.


Assuntos
Implantes Dentários , Limosilactobacillus reuteri , Peri-Implantite , Probióticos , Humanos , Peri-Implantite/terapia , Resultado do Tratamento
8.
Pflugers Arch ; 465(9): 1355-70, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23529843

RESUMO

The growth of neuritic processes in developing neurons is tightly controlled by a wide set of extracellular cues that act by initiating downstream signaling cascades, where calcium signals play a major role. Here we analyze the calcium dependence of the neurite growth promoted by basic fibroblast growth factor (bFGF or FGF-2) in chick embryonic ciliary ganglion neurons, taking advantage of dissociated, organotypic, and compartmentalized cultures. We report that signals at both the growth cone and the soma are involved in the promotion of neurite growth by the factor. Blocking calcium influx through L- and N-type voltage-dependent calcium channels and transient receptor potential canonical (TRPC) channels reduces, while release from intracellular stores does not significantly affect, the growth of neuritic processes. Simultaneous recordings of calcium signals elicited by FGF-2 at the soma and at the growth cone show that the factor activates different patterns of responses in the two compartments: steady and sustained responses at the former, oscillations at the latter. At the soma, both voltage-dependent channel and TRPC blockers strongly affect steady-state levels. At the growth cone, the changes in the oscillatory pattern are more complex; therefore, we used a tool based on wavelet analysis to obtain a quantitative evaluation of the effects of the two classes of blockers. We report that the oscillatory behavior at the growth cone is dramatically affected by all the blockers, pointing to a role for calcium influx through the two classes of channels in the generation of signals at the leading edge of the elongating neurites.


Assuntos
Sinalização do Cálcio , Fator 2 de Crescimento de Fibroblastos/farmacologia , Gânglios Parassimpáticos/metabolismo , Cones de Crescimento/metabolismo , Neuritos/metabolismo , Animais , Canais de Cálcio/metabolismo , Processos de Crescimento Celular , Embrião de Galinha , Gânglios Parassimpáticos/citologia , Gânglios Parassimpáticos/efeitos dos fármacos , Gânglios Parassimpáticos/fisiologia , Cones de Crescimento/efeitos dos fármacos , Cones de Crescimento/fisiologia , Neuritos/efeitos dos fármacos , Neuritos/fisiologia , Canais de Cátion TRPC/metabolismo
9.
Commun Biol ; 6(1): 241, 2023 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-36869080

RESUMO

One of the major problems in bioimaging, often highly underestimated, is whether features extracted for a discrimination or regression task will remain valid for a broader set of similar experiments or in the presence of unpredictable perturbations during the image acquisition process. Such an issue is even more important when it is addressed in the context of deep learning features due to the lack of a priori known relationship between the black-box descriptors (deep features) and the phenotypic properties of the biological entities under study. In this regard, the widespread use of descriptors, such as those coming from pre-trained Convolutional Neural Networks (CNNs), is hindered by the fact that they are devoid of apparent physical meaning and strongly subjected to unspecific biases, i.e., features that do not depend on the cell phenotypes, but rather on acquisition artifacts, such as brightness or texture changes, focus shifts, autofluorescence or photobleaching. The proposed Deep-Manager software platform offers the possibility to efficiently select those features having lower sensitivity to unspecific disturbances and, at the same time, a high discriminating power. Deep-Manager can be used in the context of both handcrafted and deep features. The unprecedented performances of the method are proven using five different case studies, ranging from selecting handcrafted green fluorescence protein intensity features in chemotherapy-related breast cancer cell death investigation to addressing problems related to the context of Deep Transfer Learning. Deep-Manager, freely available at https://github.com/BEEuniroma2/Deep-Manager , is suitable for use in many fields of bioimaging and is conceived to be constantly upgraded with novel image acquisition perturbations and modalities.


Assuntos
Artefatos , Processamento de Imagem Assistida por Computador , Proteínas de Fluorescência Verde , Redes Neurais de Computação , Software
10.
Eur Rev Med Pharmacol Sci ; 26(3 Suppl): 78-86, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36591881

RESUMO

OBJECTIVE: The objective of the study was to evaluate the results and immediate postoperative complications following open reduction and internal fixation of mandibular fractures with or without postoperative maxillo-mandibular fixation MATERIALS AND METHODS: The study spanned over a period of 24 months, extending from October 2015 to October 2017. The study sample comprised 24 subjects between the age range of 18 to 65 years. They were randomly divided into two groups: Group A included subjects in whom open reduction and internal fixation was followed by maxilla-mandibular fixation for 15 days, and Group B subjects in whom only open reduction and internal fixation was done, followed by immediate mobilization. The outcomes evaluated were swelling, pain, simplified oral hygiene index and occlusion. The subjects were followed for all these outcomes on 1st, 7th and 15th days. The occlusion was assessed for 5 days. Any other intra/post-operative complications were additionally noted. RESULTS: There was no statistical difference between the groups for swelling, pain and occlusion. The patients with postoperative maxilla-mandibular fixation had poorer oral hygiene when compared to the other group (p<0.001). CONCLUSIONS: The use of maxilla-mandibular fixation post open reduction and internal fixation seems to offer no additional benefits to the patients. According to the results of the study, this traditional surgical dictum seems to be used by the surgeons due to the lack of any scientific evidence. However, further studies should be conducted to confirm this statement.


Assuntos
Técnicas de Fixação da Arcada Osseodentária , Fraturas Mandibulares , Humanos , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Projetos Piloto , Técnicas de Fixação da Arcada Osseodentária/efeitos adversos , Fixação Interna de Fraturas/métodos , Fraturas Mandibulares/cirurgia , Fraturas Mandibulares/complicações , Complicações Pós-Operatórias/etiologia , Dor , Resultado do Tratamento , Placas Ósseas/efeitos adversos
11.
Eur Rev Med Pharmacol Sci ; 26(3 Suppl): 94-105, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36591877

RESUMO

OBJECTIVE: Ascorbyl palmitate is a fat-soluble ester of vitamin C and is used as an antioxidant food additive. While literature reports that ascorbyl palmitate can prevent exacerbation of pain and improve the quality of life of patients suffering from pain, this is not yet supported by clinical trial data. Our study aimed to investigate the effectiveness of ascorbyl palmitate in managing trigeminal neuralgia. PATIENTS AND METHODS: This study was carried out in a single-centre clinical trial in which subjects suffering from trigeminal neuralgia (N=11) were included. All patients were on carbamazepine when first included and, after washout period, received Ascorbyl palmitate. Eligible patients had the most severe trigeminal neuralgia pain in the oral cavity or pain on touching trigger zones, aged 20 years or older, were capable of proper assessment of the severity of pain and their condition, and had experienced multiple episodes of intraoral pain for at least 3 months with a pain intensity of more than 4 points on the numerical rating scale. The Brief Pain Questionnaire was used to evaluate patient's quality of life. RESULTS: A total of 11 patients were included with a mean age 55.36±10.67 years (7 males, 4 females). Most patients had compression by the superior cerebellar artery and vascular loops upon magnetic resonance examination. The mean numerical rating scale score for carbamazepine after one month was 7.9±0.56 (95% CI 7.49, 8.30). Similarly, for ascorbyl palmitate was 5.5±1.50 (95% CI 4.42, 6.57) (p<0.001). CONCLUSIONS: Ascorbyl palmitate can be used as an adjunct intervention in managing trigeminal neuralgia pain. According to the results, ascorbyl palmitate prevents frequent exacerbation of pain and improves patient quality of life.


Assuntos
Neuralgia do Trigêmeo , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Ascórbico/uso terapêutico , Carbamazepina/uso terapêutico , Dor , Qualidade de Vida , Neuralgia do Trigêmeo/tratamento farmacológico
12.
Sci Rep ; 10(1): 7653, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32376840

RESUMO

We describe a novel method to achieve a universal, massive, and fully automated analysis of cell motility behaviours, starting from time-lapse microscopy images. The approach was inspired by the recent successes in application of machine learning for style recognition in paintings and artistic style transfer. The originality of the method relies i) on the generation of atlas from the collection of single-cell trajectories in order to visually encode the multiple descriptors of cell motility, and ii) on the application of pre-trained Deep Learning Convolutional Neural Network architecture in order to extract relevant features to be used for classification tasks from this visual atlas. Validation tests were conducted on two different cell motility scenarios: 1) a 3D biomimetic gels of immune cells, co-cultured with breast cancer cells in organ-on-chip devices, upon treatment with an immunotherapy drug; 2) Petri dishes of clustered prostate cancer cells, upon treatment with a chemotherapy drug. For each scenario, single-cell trajectories are very accurately classified according to the presence or not of the drugs. This original approach demonstrates the existence of universal features in cell motility (a so called "motility style") which are identified by the DL approach in the rationale of discovering the unknown message in cell trajectories.


Assuntos
Antineoplásicos/farmacologia , Biologia Computacional , Ensaios de Seleção de Medicamentos Antitumorais , Aprendizado de Máquina , Algoritmos , Bioengenharia , Rastreamento de Células , Biologia Computacional/métodos , Biologia Computacional/normas , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Ensaios de Seleção de Medicamentos Antitumorais/normas , Humanos , Imagem Molecular/métodos , Reprodutibilidade dos Testes , Imagem com Lapso de Tempo
13.
Sci Rep ; 9(1): 6789, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-31043687

RESUMO

Cell-cell interactions are an observable manifestation of underlying complex biological processes occurring in response to diversified biochemical stimuli. Recent experiments with microfluidic devices and live cell imaging show that it is possible to characterize cell kinematics via computerized algorithms and unravel the effects of targeted therapies. We study the influence of spatial and temporal resolutions of time-lapse videos on motility and interaction descriptors with computational models that mimic the interaction dynamics among cells. We show that the experimental set-up of time-lapse microscopy has a direct impact on the cell tracking algorithm and on the derived numerical descriptors. We also show that, when comparing kinematic descriptors in two diverse experimental conditions, too low resolutions may alter the descriptors' discriminative power, and so the statistical significance of the difference between the two compared distributions. The conclusions derived from the computational models were experimentally confirmed by a series of video-microscopy acquisitions of co-cultures of unlabelled human cancer and immune cells embedded in 3D collagen gels within microfluidic devices. We argue that the experimental protocol of acquisition should be adapted to the specific kind of analysis involved and to the chosen descriptors in order to derive reliable conclusions and avoid biasing the interpretation of results.


Assuntos
Algoritmos , Neoplasias da Mama/metabolismo , Comunicação Celular , Rastreamento de Células/métodos , Leucócitos Mononucleares/metabolismo , Microscopia de Vídeo/métodos , Imagem com Lapso de Tempo/métodos , Neoplasias da Mama/patologia , Simulação por Computador , Feminino , Humanos , Leucócitos Mononucleares/citologia , Análise Espaço-Temporal
14.
Curr Biol ; 10(13): 758-65, 2000 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-10898977

RESUMO

BACKGROUND: Cdc42 and other Rho GTPases are conserved from yeast to humans and are thought to regulate multiple cellular functions by inducing coordinated changes in actin reorganization and by activating signaling pathways leading to specific gene expression. Direct evidence implicating upstream signals and components that regulate Cdc42 activity or for required roles of Cdc42 in activation of downstream protein kinase signaling cascades is minimal, however. Also, whereas genetic analyses have shown that Cdc42 is essential for cell viability in yeast, its potential roles in the growth and development of mammalian cells have not been directly assessed. RESULTS: To elucidate potential functions of Cdc42 mammalian cells, we used gene-targeted mutation to inactivate Cdc42 in mouse embryonic stem (ES) cells and in the mouse germline. Surprisingly, Cdc42-deficient ES cells exhibited normal proliferation and phosphorylation of mitogen- and stress-activated protein kinases. Yet Cdc42 deficiency caused very early embryonic lethality in mice and led to aberrant actin cytoskeletal organization in ES cells. Moreover, extracts from Cdc42-deficient cells failed to support phosphatidylinositol 4,5-bisphosphate (PIP(2))-induced actin polymerization. CONCLUSIONS: Our studies clearly demonstrate that Cdc42 mediates PIP(2)-induced actin assembly, and document a critical and unique role for Cdc42 in this process. Moreover, we conclude that, unexpectedly, Cdc42 is not necessary for viability or proliferation of mammalian early embryonic cells. Cdc42 is, however, absolutely required for early mammalian development.


Assuntos
Actinas/efeitos dos fármacos , Embrião de Mamíferos/fisiologia , Fosfatidilinositol 4,5-Difosfato/farmacologia , Proteína cdc42 de Ligação ao GTP/metabolismo , Actinas/metabolismo , Animais , Morte Celular , Divisão Celular , Linhagem Celular , Sobrevivência Celular , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Embrião de Mamíferos/citologia , Ativação Enzimática , Camundongos , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteína cdc42 de Ligação ao GTP/deficiência , Proteína cdc42 de Ligação ao GTP/genética
15.
Chem Biol ; 6(10): 679-87, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10508676

RESUMO

BACKGROUND: The ability to control specific protein-protein interactions conditionally in vivo would be extremely helpful for analyzing protein-protein interaction networks. SH3 (Src homology 3) modular protein binding domains are found in many signaling proteins and they play a crucial role in signal transduction by binding to proline-rich sequences. RESULTS: Random in vitro mutagenesis coupled with yeast two-hybrid screening was used to identify mutations in the second SH3 domain of Nck that render interaction with its ligand temperature sensitive. Four of the mutants were functionally temperature sensitive in mammalian cells, where temperature sensitivity was correlated with a pronounced instability of the mutant domains at the nonpermissive temperature. Two of the mutations affect conserved residues in the hydrophobic core (Val133 and Val160), suggesting a general strategy for engineering temperature-sensitive SH3-containing proteins. Indeed mutagenesis of the corresponding positions in another SH3 domain, that of Crk-1, rendered the full-length Crk-1 protein temperature sensitive for function and stability in mammalian cells. CONCLUSIONS: Construction of temperature-sensitive SH3 domains is a novel approach to regulating the function of SH3 domains in vivo. Such mutants will be valuable in dissecting SH3-mediated signaling pathways. Furthermore, the methodology described here to isolate temperature-sensitive domains should be widely applicable to any domain involved in protein-protein interactions.


Assuntos
Proteínas de Transporte/genética , Ligação Proteica/genética , Engenharia de Proteínas , Domínios de Homologia de src/genética , Sequência de Aminoácidos , Linhagem Celular , Análise Mutacional de DNA , Humanos , Dados de Sequência Molecular , Mutagênese , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas c-crk , Transdução de Sinais , Temperatura
16.
Clin Exp Rheumatol ; 9 Suppl 6: 21-8, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-2060173

RESUMO

The introduction of reliable and non-invasive methods of measuring bone mass has allowed investigators to study the bone mass loss (ostopenia) related to rheumatic diseases and corticosteroid therapy. Serial measurements of lumbar bone mineral density (BMD) by dual-photon absorptiometry (DPA) is an effective method of checking bone mineralisation. In children, however, the bone mass is not constant over time, so bone densitometric measurements must take into account not only the net loss but also the missing increase in BMD. In order to study the effects of both chronic rheumatic disease and the long-term administration of corticosteroids in children, as a first step the reference curves of bone mineralisation (mean BMD values and annual % BMD growth rates) were calculated from a control population of 79 children (32 males and 47 females) aged 3 to 20 years. All the subjects involved in the study underwent DPA utilising a Norland Bonestar instrument provided with a 153 Gadolinium source and the average BMD (g/cm2) of the lumbar spine was calculated. As a second step, a transverse study was carried out on a series of 157 children and young adults affected by chronic rheumatic diseases with juvenile onset. As a third step, a longitudinal study on the adverse effect of the chronic administration of corticosteroids on bone mineralisation was carried out on a series of 58 patients affected by chronic rheumatic diseases with juvenile onset who were being treated with long-term corticosteroids. Serial measurements of bone mass should help us to improve our strategies in preventing and counteracting osteopenia due to the chronic administration of corticosteroids also in children.


Assuntos
Corticosteroides/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Doenças Reumáticas/metabolismo , Absorciometria de Fóton , Adolescente , Corticosteroides/efeitos adversos , Adulto , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Valores de Referência , Análise de Regressão , Doenças Reumáticas/tratamento farmacológico , Fatores de Tempo
17.
Mutat Res ; 285(2): 239-49, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7678897

RESUMO

A great deal of the flower cultivation in Italy is carried out in the western part of the Region of Liguria. The extensive use of pesticides professionally exposes floriculturists operating in this area to a complex mixture of compounds. The frequency of micronuclei in peripheral lymphocytes has been evaluated in 71 floriculturists and in a control group of 75 healthy blood donors living in the area. No correlation between age and micronucleus frequency was found in peripheral lymphocytes of the controls while an increase in this parameter was observed in the elderly of the exposed group. Our data suggest a sex-related effect in the induction of micronuclei. The frequencies of micronucleated lymphocytes were significantly higher in females than in males in both exposed and control groups (RR = 1.45, 95% C.I. 1.25-1.67). The main result of this study, however, is the observation of a significant increase in micronucleated lymphocyte frequency in people occupationally exposed to pesticides. The micronucleus frequency was 8.57/1000 for exposed persons and 6.67/1000 for controls (p < 0.05). A dose-response relationship with duration of exposure was apparent with a maximum increment of 71% in the frequency of micronuclei in subjects exposed for over 30 years.


Assuntos
Cromossomos Humanos/efeitos dos fármacos , Praguicidas/toxicidade , Adulto , Idoso , Feminino , Humanos , Itália , Masculino , Testes para Micronúcleos , Pessoa de Meia-Idade , Exposição Ocupacional , Distribuição Aleatória , Análise de Regressão , Fumar , Fatores de Tempo
18.
Mutat Res ; 256(1): 13-20, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1944383

RESUMO

This work is part of a research project on 2 groups of tannery workers (i.e., workers employed in the tanning process and those employed in the finishing department), and 2 control groups consisting of individuals paired with each exposed person according to sex, age and smoking habit. The whole study included the evaluation of micronuclei as well as of chromosomal aberrations and sister-chromatid exchanges in peripheral blood lymphocytes. Data on micronucleus analysis in both controls and exposed persons are shown in this paper. There was no statistically significant difference between MN frequencies in the 2 groups of exposed and controls, nor any positive correlation with smoking habit. The effect of age on basal frequency of micronucleated cells clearly emerges in the present study: both controls and exposed show an increase in MN frequency due to age. This could be correlated with a higher sensitivity to breaks, rearrangements or aneuploidogenic events of circulating lymphocytes in aged people.


Assuntos
Envelhecimento/genética , Aberrações Cromossômicas , Testes para Micronúcleos , Exposição Ocupacional , Curtume , Adulto , Envelhecimento/sangue , Poluentes Ambientais/sangue , Humanos , Linfócitos/patologia , Masculino , Micronúcleos com Defeito Cromossômico/patologia , Pessoa de Meia-Idade , Troca de Cromátide Irmã , Fumar/sangue , Fumar/genética
19.
Clin Nephrol ; 35(3): 98-104, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2032403

RESUMO

Preliminary results of the efficacy of high-dose intravenous human IgG in patients with biopsy-confirmed idiopathic membranous nephropathy (IMGN) were reported. Five patients with normal renal function (creatinine clearance 125.2 +/- 16 ml/min/1.73 m2 BSA) (Group A) and 4 patients with moderate renal insufficiency (creatinine clearance 65.5 +/- 8.3 ml/min/1.73 m2 BSA) (Group B) received pulse doses of IgG (0.4 g/kg BW) for 3 consecutive days; these 3-day boli were repeated 3 times at 21-day intervals; since then for a 10-month period one bolus once every 3 weeks has been administered. Five responder patients at the end of the trial received a new renal biopsy. In 4 Group A patients complete remission of proteinuria (daily proteinuria less than 0.2 g) was observed, whereas 1 patient showed partial remission (proteinuria 2 g/day). In Group B patients, 1 showed complete remission and 2 partial remission; in 1 patient no variation of proteinuria was noted. In responder patients clinical and biological findings of the nephrotic syndrome disappeared and a statistically significant increase of creatinine clearance was observed. In control biopsies at the end of the trial the immunofluorescence staining failed to find immunodeposits and recovery of glomerular lesions at light microscopy. In conclusion, IgG therapy seems to be of benefit to patients with IMGN but a randomized clinical trial to confirm this preliminary report is needed.


Assuntos
Glomerulonefrite Membranosa/terapia , Imunoglobulina G/uso terapêutico , Adulto , Feminino , Glomerulonefrite Membranosa/imunologia , Glomerulonefrite Membranosa/patologia , Humanos , Imunização Passiva , Rim/imunologia , Rim/patologia , Testes de Função Renal , Masculino , Pessoa de Meia-Idade
20.
Int J Clin Pharmacol Res ; 14(1): 35-43, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7927959

RESUMO

The antiproteinuric effect of angiotensin converting enzyme (ACE) inhibition in patients with renal disease is well known, but the results of clinical studies appear to vary considerably from a partial decrease to a fall of 100% in urinary protein excretion. This may have been due to the use of different doses of ACE inhibitor, different renal pathology and non-standardized sodium intake. In 16 proteinuric patients with biopsy-proven IgA nephropathy, with normal renal function and blood pressure, maintained at controlled sodium intake < or = 80 mEqII, the efficacy of increasing doses of the ACE inhibitor lisinopril was studied. The lisinopril doses were 5, 10, 15 and 20 mg, administered for 4 weeks. Between each dose increment a placebo period of 3 weeks was interposed. Proteinuria stepwise decreased from the control period by 39%, 44%, 61% and 67% with lisinopril at 5, 10, 15 and 20 mg, respectively. The blood pressure decreased by 22% with lisinopril 5 mg; a similar fall was observed with the dose increment. Although the glomerular filtration rate remained unchanged, the renal plasma flow increased by 21%, 26%, 24% and 28% and the filtration fraction increased by 28% mean. The ACE plasma levels decreased by 33%, 64%, 76% and 83%. A close correlation was found between an increase in lisinopril dosage and the fall in urinary protein excretion (r = 0.88, p < 0.001). The antiproteinuric effect of lisinopril is dose-related and may be attributable to some extent to the fall in systemic (and intraglomerular) blood pressure, but it is best attributed to the modification of glomerular sieving function.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Pressão Sanguínea/fisiologia , Glomerulonefrite por IGA/tratamento farmacológico , Rim/fisiologia , Lisinopril/uso terapêutico , Proteinúria/tratamento farmacológico , Adulto , Pressão Sanguínea/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Taxa de Filtração Glomerular , Glomerulonefrite por IGA/sangue , Glomerulonefrite por IGA/fisiopatologia , Humanos , Lisinopril/administração & dosagem , Masculino , Pessoa de Meia-Idade , Peptidil Dipeptidase A/sangue
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