Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
World J Microbiol Biotechnol ; 40(12): 374, 2024 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-39487367

RESUMO

Astaxanthin is a bioactive natural pigment with antioxidant properties. It has extensive applications within the industrial sector as well as in human and animal health. Mucor circinelloides is a zygomycete fungus that accumulates ß-carotene as the main carotenoid compound. M. circinelloides is a well-known model organism among Mucorales for studying carotenogenesis in fungi, which makes it a promising candidate for the biotechnological production of carotenoids. In this study, ß-carotene hydroxylase (crtR-B) and ketolase (bkt) genes (codon-optimized) were coexpressed from Haematococcus pluvialis in M. circinelloides using two potent promoters gpd1 and zrt1 respectively to generate an astaxanthin-producing biofactory. Following 72 h of cultivation, the recombinant M. circinelloides Mc-57 obtained in this study produced 135 ± 8 µg/g of astaxanthin. This is the highest reported amount in M. circinelloides to date. The mRNA levels of crtR-B and bkt in Mc-57 were assayed using RT-qPCR. These levels showed a 5.7-fold increase at 72 h and a 5.5-fold increase at 24 h, respectively, compared to the control strain. This demonstrated the successful overexpression of both genes, which correlated with the production of astaxanthin in the Mc-57. Moreover, the addition of glutamate (2 g/L) and mevalonate (15 mM) resulted in an increase in astaxanthin production in the recombinant strain. The results showed that the combined addition of these metabolic precursors resulted in 281 ± 20 µg/g of astaxanthin, which is 2.08-fold higher than the control medium (135 ± 8 µg/g). The addition of metabolic precursors also positively impacted the biomass growth of Mc-57, reaching 11.2 ± 0.57 g/L compared to 9.1 ± 0.23 g/L (control medium). The study successfully addressed the challenge of balancing the accumulation of astaxanthin with biomass growth, which has been regarded as common bottleneck in the metabolic engineering of microbial cells. The development of a recombinant fungal strain of M. circinelloides not only increased astaxanthin content. Additionally, it provided a foundation for further improvement of the biotechnological production of astaxanthin in M. circinelloides.


Assuntos
Engenharia Metabólica , Oxigenases de Função Mista , Mucor , Xantofilas , Xantofilas/metabolismo , Mucor/genética , Mucor/metabolismo , Mucor/crescimento & desenvolvimento , Engenharia Metabólica/métodos , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Oxigenases/genética , Oxigenases/metabolismo , Regiões Promotoras Genéticas , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Clorofíceas/genética , Clorofíceas/metabolismo
2.
AAPS PharmSciTech ; 18(6): 1998-2010, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27933585

RESUMO

The liquid and semisolid matrix technology, filling liquids, semi-solids and gels in hard gelatin capsule are promising, thus, there is a need of enhanced research interest in the technology. Therefore, the present study was aimed to investigate isoniazid (freely soluble) and metronidazole (slightly soluble) gels filled in hard gelatin capsules for the effect of poloxamers of different viscosities on release of the drugs. Gel of each drug (10% w/w, particle size 180-250 µm), prepared by mixing poloxamer and 8% w/w hydrophilic silicon dioxide (Aerosil® A200), was assessed for rheology, dispersion stability and release profile. Both the drugs remained dispersed in majority of gels for more than 30 days, and dispersions were depended on gels' viscosity, which was further depended on viscosity of poloxamers. A small change in viscosity was noted in gels on storage. FTIR spectra indicated no interactions between components of the gels. The gels exhibited thixotropic and shear-thinning behaviour, which were suitable for filling in hard gelatin capsules without any leakage from the capsules. The release of both drugs from the phase-stable gels for 30 days followed first-order kinetics and was found to be correlated to drugs' solubility, poloxamers' viscosity, polyoxyethylene contents and proportion of block copolymer (poloxamers) in the gels. The findings of the present study indicated that release of drugs of different solubilities (isoniazid and metronidazole) might be modified from gels using different poloxamers and Aerosil® A200.


Assuntos
Gelatina/farmacocinética , Poloxâmero/farmacocinética , Reologia/métodos , Dióxido de Silício/farmacocinética , Cápsulas , Gelatina/química , Géis , Tamanho da Partícula , Poloxâmero/química , Dióxido de Silício/química , Solubilidade , Viscosidade
3.
J Appl Toxicol ; 33(10): 1036-43, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22886793

RESUMO

There is an increasing belief that organophosphorus compounds (OPCs) impair glucose homeostasis and cause hyperglycemia and diabetes mellitus. The present study was undertaken to investigate the putative diabetogenic effect of sub-lethal and sub-chronic exposure to paraoxon (POX), an extremely hazardous OPC used in pesticides. The effect of paraoxon on streptozotocin-induced diabetic rats was also examined. Each rat was injected with 100 nmol of POX 5 days per week for 6 weeks. Blood glucose levels and red blood cell acetylcholinesterase activity were measured weekly. Biochemical analysis and morphological studies were performed at the end of the experiment. The results revealed that POX neither induces nor exacerbates diabetes mellitus in experimental rats. Liver and kidney/body weight ratios revealed statistically insignificant differences when compared with controls. Biochemical analysis of urine samples showed a small but not significant increase in protein level in all groups. Urine bilirubin was significantly higher in the diabetes + POX group when compared with the control group. The number of blood cells in urine was significantly higher in the POX-treated group compared with the control group. Hyperglycemia was noted in the diabetes and diabetes + POX groups, but neither in the saline control nor in POX-treated normal rats. Electron microscopy of POX-treated pancreas did not show any morphological changes in beta cells. These results suggest that POX does not cause diabetes mellitus at sub-lethal sub-chronic exposure.


Assuntos
Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/patologia , Paraoxon/toxicidade , Praguicidas/toxicidade , Acetilcolinesterase/metabolismo , Animais , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Masculino , Microscopia Eletrônica , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Wistar , Estreptozocina , Testes de Toxicidade Subcrônica
4.
Acta Pol Pharm ; 70(4): 749-57, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23923399

RESUMO

Gliclazide is an oral hypoglycemic agent, indicated in non insulin dependent diabetes mellitus and in patients with diabetic retinopathy. It has good tolerability and is a short acting sulfonyl urea that requires large dose to maintain the blood glucose level. So development of a sustained release formulation of gliclazide (GLZ) is required for better patient compliance. This study was conducted to assess the effects of different drug polymer ratios on the release profile of gliclazide from the matrix. Oral matrix tablets of gliclazide were prepared by hot melt method, using pure and blended mixture of glyceryl monostearate (GMS) and stearic acid (SA) in different ratios. In vitro release pattern was studied for 8 h in phosphate buffer media (pH 7.4). Different kinetic models including zero order, first order, Higuchi and Peppas were applied to evaluate drug release behavior. Drug excipient compatibility was evaluated by scanning with DSC and FTIR. Higuchi model was found the most appropriate model for describing the release profile of GLZ and non-Fickian release was found predominant mechanism of drug release. The release of drug from the matrix was greatly controlled by GMS while SA appeared to facilitate the release of drug from matrix tablets. FTIR results showed no chemical interaction between drug and the polymers, and DSC results indicated amorphous state of GLZ and polymers without significant complex formation. The results indicate that matrix tablets of gliclazide using glyceryl monostearate and stearic acid showed marked sustained release properties.


Assuntos
Excipientes/química , Gliclazida/química , Glicerídeos/química , Hipoglicemiantes/química , Ácidos Esteáricos/química , Administração Oral , Soluções Tampão , Varredura Diferencial de Calorimetria , Química Farmacêutica , Preparações de Ação Retardada , Estabilidade de Medicamentos , Gliclazida/administração & dosagem , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Hipoglicemiantes/administração & dosagem , Cinética , Modelos Químicos , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Comprimidos , Tecnologia Farmacêutica/métodos
5.
Drugs Context ; 122023.
Artigo em Inglês | MEDLINE | ID: mdl-38148829

RESUMO

Background: Gastroparesis is a serious condition that can be caused by diabetes, surgery or infection, or can be idiopathic. When there is no mechanical obstruction, gastroparesis is characterized by delayed stomach emptying. Itopride, a prokinetic drug, inhibits acetylcholinesterase activity in addition to antagonizing dopamine D2 receptors. Methods: This prospective, multicentre study is based on real-world data from 988 patients with a diagnosis of diabetic gastroparesis for index (PAGI-SYM2) evaluation at baseline and week 4 of treatment for upper gastrointestinal disorder symptoms. Results: Upper gastrointestinal symptom severity scores improved significantly after 4 weeks of treatment (p<0.001), with significant improvement across all categories of gastroparesis (very mild (37-58.6%), mild degree (24.6-31.6%), moderate (29.3-7.3%) and severe (8.8-2.6%). Conclusion: Itopride SR (Nogerd SR) in a 150 mg once-daily dose showed promising results in reducing the severity of upper gastrointestinal disorder symptoms associated with diabetic gastroparesis. Both statistical and clinical effectiveness were observed. Moreover, the treatment demonstrated a favourable tolerability profile, with a low incidence of adverse effects.

6.
Life (Basel) ; 12(8)2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-36013400

RESUMO

(1) Background: Cardiovascular complications are a leading cause of morbidity and mortality in diabetic patients. The effects of obesity and diabesity on the function and structure of ventricular myocytes in the Zucker fatty (ZF) rat and the Zucker diabetic fatty (ZDF) rat compared to Zucker lean (ZL) control rats have been investigated. (2) Methods: Shortening and intracellular Ca2+ were simultaneously measured with cell imaging and fluorescence photometry, respectively. Ventricular muscle protein expression and structure were investigated with Western blot and electron microscopy, respectively. (3) Results: The amplitude of shortening was increased in ZF compared to ZL but not compared to ZDF myocytes. Resting Ca2+ was increased in ZDF compared to ZL myocytes. Time to half decay of the Ca2+ transient was prolonged in ZDF compared to ZL and was reduced in ZF compared to ZL myocytes. Changes in expression of proteins associated with cardiac muscle contraction are presented. Structurally, there were reductions in sarcomere length in ZDF and ZF compared to ZL and reductions in mitochondria count in ZF compared to ZDF and ZL myocytes. (4) Conclusions: Alterations in ventricular muscle proteins and structure may partly underlie the defects observed in Ca2+ signaling in ZDF and ZF compared to ZL rat hearts.

7.
Curr Drug Deliv ; 19(7): 801-811, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34477519

RESUMO

INTRODUCTION: Liquid Semisolid Matrix (LSSM) technology involves the filling of drugmixed gel in hard gelatin capsules for different applications. METHODS: In continuation of our previous work on LSSM technology, 10% (w/w) of practically insoluble model drug, mefenamic acid was incorporated in gels of different poloxamers with 8% (w/w) SiO2. RESULTS: Gels exhibited plasticity or pseudoplasticity along thixotropy at 2 and 24 h enabling their easy filling into hard gelatin capsules without content seepage. Mefenamic acid gels prepared with L64 and L92 maintained their apparent viscosities for the study period of one month. Around 100% mefenamic acid was released within 90 min from L64- and in 150 min from L92-SiO2 gels, both with first-order kinetics. In 12 month long-term stability studies, only mefenamic acid-L64- SiO gel at 30°C/65% RH indicated dispersion stability with similar rheology and release pattern to that at 2, 24 and 30 days. No chemical drug-polymer interactions were found in FTIR. CONCLUSION: The release of practically insoluble mefenamic acid could be enhanced from gel formulated with L64 and SiO2.


Assuntos
Ácido Mefenâmico , Poloxâmero , Cápsulas , Gelatina/química , Géis/química , Ácido Mefenâmico/química , Poloxâmero/química , Reologia , Sílica Gel , Dióxido de Silício , Tecnologia
8.
Biomolecules ; 13(1)2022 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-36671407

RESUMO

The development of animal models to study cell death in the brain is a delicate task. One of the models, that was discovered in the late eighties, is the induction of neurodegeneration through glucocorticoid withdrawal by adrenalectomy in albino rats. Such a model is one of the few noninvasive models for studying neurodegeneration. In the present study, using stereological technique and ultrastructural examination, we aimed to investigate the impact of short-term adrenalectomy (2 weeks) on different hippocampal neuronal populations in Wistar rats. In addition, the underlying mechanism(s) of degeneration in these neurons were investigated by measuring the levels of insulin-like growth factor-1 (IGF-1) and ß-nerve growth factor (ß-NGF). Moreover, we examined whether the biochemical and histological changes in the hippocampus, after short-term adrenalectomy, have an impact on the cognitive behavior of Wistar rats. Stereological counting in the hippocampus revealed significant neuronal deaths in the dentate gyrus and CA4/CA3, but not in the CA2 and CA1 areas, 7 and 14 days post adrenalectomy. The ultrastructural examinations revealed degenerated and degenerating neurons in the dentate, as well as CA4, and CA3 areas, over the course of 3, 7 and 14 days. The levels of IGF-1 were significantly decreased in the hippocampus of ADX rats 24 h post adrenalectomy, and lasted over the course of two weeks. However, ß-NGF was not affected in rats. Using a passive avoidance task, we found a cognitive deficit in the ADX compared to the SHAM operated rats over time (3, 7, and 14 days). In conclusion, both granule and pyramidal cells were degenerated in the hippocampus following short-term adrenalectomy. The early depletion of IGF-1 might play a role in hippocampal neuronal degeneration. Consequently, the loss of the hippocampal neurons after adrenalectomy leads to cognitive deficits.


Assuntos
Adrenalectomia , Fator de Crescimento Insulin-Like I , Animais , Ratos , Ratos Wistar , Fator de Crescimento Insulin-Like I/metabolismo , Hipocampo/metabolismo , Neurônios/metabolismo
9.
Acta Pol Pharm ; 68(6): 919-25, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22125958

RESUMO

This study was designed to evaluate the hypoglycemic effects of different plant extracts in single and in combined formulation, in experimentally induced "diabetic rabbits". The extracts were obtained from seeds of Syzygium jambolana, fruits of Momordica charantia and leaves of Azadirachta indica. Treatment of diabetes with plant extracts was started at 8 days after alloxan injection. Rabbits were randomly divided into four groups, each group consisting of six rabbits. Each group of rabbits was given a dose of granules containing 200 mg/kg b.w. concentrated ethanolic extract of a plant while the fourth group was given a dose of granules consisting of combined extract of all three folk plants. Blood samples were drawn at 0, 2, 4, 8, 12, 24, 36, 48, 72 and 96 h. Serum glucose estimation was done by glucose oxidase kit method. Anti-diabetic effect was produced after 72 h in groups 1, 2 and 3 that were administered with a dose of granules of ethanolic extract of single plant but in group 4, treated with 200 mg/kg body weight of combined extract of all three plants, hypoglycemic effect was produced after 96 h. Hypoglycemic effects may be induced in rabbits by administration of extracts of various plant parts. The hypoglycemic effect produced by granules of single plant extract was more pronounced than antidiabetic effect produced by combining three extracts in a single formulation.


Assuntos
Azadirachta , Glicemia/efeitos dos fármacos , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Momordica charantia , Extratos Vegetais/farmacologia , Syzygium , Animais , Azadirachta/química , Glicemia/metabolismo , Química Farmacêutica , Diabetes Mellitus Experimental/sangue , Composição de Medicamentos , Quimioterapia Combinada , Etanol/química , Frutas , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Momordica charantia/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Folhas de Planta , Plantas Medicinais , Coelhos , Sementes , Solventes/química , Syzygium/química , Fatores de Tempo
10.
Beilstein J Nanotechnol ; 12: 1339-1364, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34934608

RESUMO

In this study, poly(isobutylene-alt-maleic anhydride) (PMA)-coated spinel ferrite (MFe2O4, where M = Fe, Co, Ni, or Zn) nanoparticles (NPs) were developed as carriers of the anticancer drugs doxorubicin (DOX) and methotrexate (MTX). Physical characterizations confirmed the formation of pure cubic structures (14-22 nm) with magnetic properties. Drug-loaded NPs exhibited tumor specificity with significantly higher (p < 0.005) drug release in an acidic environment (pH 5.5). The nanoparticles were highly colloidal (zeta potential = -35 to -26 mV) in deionized water, phosphate buffer saline (PBS), and sodium borate buffer (SBB). They showed elevated and dose-dependent cytotoxicity in vitro compared to free drug controls. The IC50 values ranged from 0.81 to 3.97 µg/mL for HepG2 and HT144 cells, whereas IC50 values for normal lymphocytes were 10 to 35 times higher (18.35-43.04 µg/mL). Cobalt ferrite (CFO) and zinc ferrite (ZFO) NPs were highly genotoxic (p < 0.05) in cancer cell lines. The nanoparticles caused cytotoxicity via oxidative stress, causing DNA damage and activation of p53-mediated cell cycle arrest (significantly elevated expression, p < 0.005, majorly G1 and G2/M arrest) and apoptosis. Cytotoxicity testing in 3D spheroids showed significant (p < 0.05) reduction in spheroid diameter and up to 74 ± 8.9% of cell death after two weeks. In addition, they also inhibited multidrug resistance (MDR) pump activity in both cell lines suggesting effectivity in MDR cancers. Among the tested MFe2O4 NPs, CFO nanocarriers were the most favorable for targeted cancer therapy due to excellent magnetic, colloidal, cytotoxic, and biocompatible aspects. However, detailed mechanistic, in vivo cytotoxicity, and magnetic-field-assisted studies are required to fully exploit these nanocarriers in therapeutic applications.

11.
J Ayub Med Coll Abbottabad ; 33(3): 441-446, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34487653

RESUMO

BACKGROUND: Optical Coherence Tomography Angiography (OCTA) is dye less microvascular visualizing technique. In study we binaries OCTA images of macular vessels in healthy and diabetic subjects without macular oedema using Adobe Photoshop CS3 extended version. METHODS: Prospective, single centered, observational study total of 58 eyes of 108 Diabetic Retinopathy (DR) subjects and 20 eyes of 40 normal subjects with mean age of 58.3±10.5 range (40-82) were included in our study. Ten eyes with Non-Diabetic Retinopathy (NDR), twenty-nine eyes with Non-Proliferative Diabetic Retinopathy (NPDR) (mild-10, moderate-7 and severe-12) and nineteen eyes with Proliferative Diabetic Retinopathy (PDR)are studied with images obtained using OCTA between September 2016 to June 2017. Scan area of 6×6 mm was selected to find morphological changes in the superficial retinal layers and deep retinal layers. Captured OCTA images were binarized using automated thresholding algorithm. Macular Vessel Density (MVD) (%) and Foveal Avascular Zone area (mm2) measured for superficial and deep retinal vessel arcade. For comparison, analysis of variance and Kruskal-Wallis test are applied. RESULTS: Diabetic eyes were grouped according to their severity level. MVD and FAZ are compared in all groups. Results are significantly lower in all groups except in controls and NDR. Significant decrease is observed in vascular density of most layers with progress in retinopathy. CONCLUSIONS: Adobe Photoshop CS3 extended version is an excellent tool for image binarization. Calculating FAZ area and MVD using OCTA images agreed closely with clinical grading system. Application of this method can be helpful in monitoring disease progression.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Idoso , Retinopatia Diabética/diagnóstico por imagem , Angiofluoresceinografia , Fóvea Central , Fundo de Olho , Humanos , Densidade Microvascular , Pessoa de Meia-Idade , Estudos Prospectivos , Software , Tomografia de Coerência Óptica
12.
Accid Anal Prev ; 123: 12-19, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30448708

RESUMO

Motorcycles constitute 61% of the total registered vehicles in Pakistan and there has been a 371% growth in motorcycles in the country from year 2005-2015. Motorcycle is an essential and popular mode of transportation in Pakistan, therefore, the present study estimated a random parameters logit model to investigate the factors influencing the motorcycle injury severity using motorcycle crash data of Rawalpindi city collected by the Provincial Emergency Response Service. No injury, minor injury, severe injury and fatal injury are used as four categories of motorcyclist injury severity levels to calibrate the model. Mainly the effects of speed limits, crash-specific factors, rider attributes, roadway characteristics, weather and socio-demographics factors are considered for motorcycle-injury severity analysis. It was revealed that probability of fatal/severe injury increases for crashes: involving middle-aged riders (25-50 years) and riders with no education, occurring on roads with posted speed limit of 70 kms per hour or higher, crashes involving a motorcycle and a heavy vehicle, involving collision of a motorcycle with a fixed object and occurring during dry weather conditions. Also, the probability of minor injury increases for crashes: occurring on divided streets and road segments with a posted speed limit of less than 50 kms per hour, involving Chinese brand motorcycles, involving registered motorcycles, and where at least one motorcycle and auto rickshaw is involved. The research findings suggest that besides measures to control/ reduce the risky motorcyclists behavior there is a need to lower speed limits on roads with a higher motorcycle proportion, separate motorcycles from heavy vehicles and removal of fixed objects from the roadside. Besides data limitations, results are expected to generate more discussion and interest in motorcycle safety in the country and can be used by the enforcement agencies to improve/ enhance the current state of motorcycle safety in the country.


Assuntos
Acidentes de Trânsito/mortalidade , Motocicletas/estatística & dados numéricos , Ferimentos e Lesões/epidemiologia , Acidentes de Trânsito/prevenção & controle , Adulto , Serviços Médicos de Emergência/estatística & dados numéricos , Humanos , Escala de Gravidade do Ferimento , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Assunção de Riscos
13.
Accid Anal Prev ; 123: 39-50, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30463029

RESUMO

This paper examined the accident risk factors associated with highway traffic and roadway design, for each of three highway classes in the United States using a bivariate modeling framework involving two levels of accident severity. With regard to the highest class (Interstates), the results suggest that, compared to no-casualty accidents, casualty accidents are more sensitive to traffic volume and average vertical grade, but less sensitive to the inside shoulder width and the median width. For US Roads, it was determined that, compared to no-casualty accidents, casualty accidents are more sensitive to traffic volume, outside shoulder width, pavement condition, and median width but less sensitive to the average vertical grade. For the relatively lowest-class roads (State Roads), it was determined that, compared to no-casualty accidents, casualty accidents are more sensitive to the traffic volume, lane width, outside shoulder width, and pavement condition. Compared to the relatively lower-class highways, accidents at higher-class highways are more sensitive to: changes in traffic volume, average vertical grade, median width, inside shoulder width, and the pavement condition (no-casualty accidents only); but less sensitive to changes in lane width, pavement condition (casualty accidents only), and the outside shoulder width. This variation in sensitivity across the different road classes could be attributed to the differences in road geometry standards across the road classes, as the results seem to support the hypothesis that these standards strongly influence accident occurrence. It is hoped that the developed bivariate negative binomial models can help highway engineers to evaluate their current design standards and policy, and to assess the safety consequences of changes in these standards in each road class.


Assuntos
Acidentes de Trânsito/estatística & dados numéricos , Ambiente Construído/classificação , Ambiente Construído/estatística & dados numéricos , Segurança , Ambiente Construído/normas , Humanos , Modelos Estatísticos , Fatores de Risco , Estados Unidos
14.
Math Biosci Eng ; 16(5): 3285-3310, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-31499614

RESUMO

Transforming growth factor beta1 (TGFß1) and matrix metalloproteinase-9 (MMP-9) have been associated with migration and invasion in hepatocellular carcinoma (HCC). Recent studies have suggested a positive feedback loop between TGFß1 and MMP-9 mediated by the PI3K signaling pathway that confers acquired invasion and metastasis in HCC via induction of the epithelial-mesenchymal transition (EMT), which grows into invasive carcinoma. But the potential molecular mechanism of this loop on HCC has not been clarified yet. Therefore, this study is designed to explore the association between the two entities and their key determinants such as NFκB, TIMP-1, and hepatic stellate cells (HSCs). Hence, a qualitative modeling framework is implemented that predict the role of biological regulatory network (BRN) during recovery and HCC metastasis. Qualitative modeling predicts discrete trajectories, stable states, and cycles that highlight the paths leading to disease recovery and homeostasis, respectively. The deadlock stable state (1, 1, 1, 1, 1) predicts high expression of all the entities in the BRN, resulting in the progression of HCC. The qualitative model predicts 30 cycles representing significant paths leading to recovery and homeostasis and amongst these the most significant discrete cycle was selected based on the highest betweenness centralities of the discrete states. We further verified our model with network modeling and simulation analysis based on petri net modeling approach. The BRN dynamics were analyzed over time. The results implied that over the course of disease condition or homeostasis, the biological entities are activated in a variable manner. Taken together, our findings suggest that the TGFß1 and the MMP-9 feedback loop is critical in tumor progression, as it may aid in the development of treatment strategies that are designed to target both TGFß and MMP-9.


Assuntos
Carcinoma Hepatocelular/metabolismo , Regulação da Expressão Gênica , Neoplasias Hepáticas/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Algoritmos , Simulação por Computador , Citocinas/metabolismo , Progressão da Doença , Homeostase , Humanos , Modelos Teóricos , Invasividade Neoplásica , Metástase Neoplásica , Transdução de Sinais
15.
Ocul Immunol Inflamm ; 15(6): 447-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18085490

RESUMO

PURPOSE: To report bilateral ocular hypertension in association with ocular sarcoidosis. METHODS: Case note review of patients with a diagnosis of sarcoidosis-related uveitis. RESULTS: The authors identified 5 patients who fulfilled the diagnostic criteria for ocular sarcoidosis and who had intraocular pressures of > 40 mmHg in each eye. CONCLUSIONS: Physicians should be aware of the association of raised intraocular pressure with ocular sarcoidosis.


Assuntos
Hipertensão Ocular/etiologia , Sarcoidose/complicações , Uveíte/complicações , Adulto , Idoso , Feminino , Humanos , Pressão Intraocular , Masculino , Pessoa de Meia-Idade , Sarcoidose/diagnóstico , Uveíte/diagnóstico
16.
Front Physiol ; 8: 416, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28659828

RESUMO

Cellular homeostasis is a continuous phenomenon that if compromised can lead to several disorders including cancer. There is a need to understand the dynamics of cellular proliferation to get deeper insights into the prevalence of cancer. Mechanistic Target of Rapamycin (mTOR) is implicated as the central regulator of the metabolic pathway involved in growth whereas its two distinct complexes mTORC1 and mTORC2 perform particular functions in cellular propagation. To date, mTORC1 is a well defined therapeutic target to inhibit uncontrolled cell division, while the role of mTORC2 is not well characterized. Therefore, the current study is designed to understand the signaling dynamics of mTOR and its partner proteins such as PI3K, PTEN, mTORC2, PKB (Akt), mTORC1, and FOXO. For this purpose, a qualitative model of mTOR-associated Biological Regulatory Network (BRN) is constructed to predict its regulatory behaviors which may not be predictable otherwise. The depleted expression of PTEN and FOXO along with the overexpression of PI3K, mTORC2, mTORC1 and Akt is predicted as a stable steady state which is in accordance with their observed expression levels in the progression of various cancers. The qualitative model also predicts the homeostasis of all the entities in the form of qualitative cycles. The significant qualitative (discrete) cycle is identified by analyzing betweenness centralities of the qualitative (discrete) states. This cycle is further refined as a linear hybrid automaton model with the production (activation) and degradation (inhibition) time delays in order to analyze the real-time constraints for its existence. The analysis of the hybrid model provides a formal proof that during homeostasis the inhibition time delay of Akt is less than the inhibition time delay of mTORC2. In conclusion, our observations characterize that in homeostasis Akt is degraded with a faster rate than mTORC2 which suggests that the inhibition of Akt along with the activation of mTORC2 may be a better therapeutic strategy for the treatment of cancer.

17.
Ann N Y Acad Sci ; 1084: 361-70, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17151315

RESUMO

The C57BL/6J mice are inbred strains and develop the metabolic syndrome of obesity, hyperinsulinemia, hyperglycemia, and hypertension, when fed a high-fat diet. These features are similar to those observed in the human metabolic syndrome. This article examined the effect of fat-enriched (FE) diet on the pattern of distribution of insulin-, glucagon-, somatostatin-, and pancreatic polypeptide (PP)-positive cells in the pancreatic islets of C57BL/6J mice using immunohistochemical methods. Insulin-immunoreactive cells were observed in both the peripheral and central regions of the islets of Langerhans in both FE- and control diet-fed mice. The percentage distribution of insulin-positive cells was similar in FE (83.5 +/- 6.4) compared to control diet-fed C57BL/6J mice (83.8 +/- 6.5). Glucagon-containing cells were discerned in the periphery of pancreatic islets in both FE- and control diet-fed mice. The percentage distribution of glucagon was not statistically different in mice fed with FE (9.9 +/- 2.7) compared to control diet (11.3 +/- 4.9). Somatostatin-positive cells were seen in the outer part of the islet of Langerhans and constitute 12.1% (+/-6.3) and 10% (+/-5.5) of pancreatic islet cells in FE- and control diet-fed mice, respectively. PP-immunoreactive cells were observed in the peripheral region of the pancreatic islets of both FE- and control diet-fed mice. The percentage distribution of PP-positive cells was significantly (2.0 +/- 1.2) lower compared to control (5.1 +/- 2.4). In conclusion, the number of PP is significantly reduced in FE diet-fed mice and may play a role in the pathogenesis of diet-induced metabolic syndrome in C57BL/6J mice.


Assuntos
Gorduras na Dieta/farmacologia , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/fisiologia , Animais , Imuno-Histoquímica , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/ultraestrutura , Tecido Linfoide/citologia , Tecido Linfoide/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL
18.
Ocul Immunol Inflamm ; 13(1): 67-71, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15804772

RESUMO

PURPOSE: To evaluate the efficacy of deep intramuscular methylprednisolone (IMMP) in the treatment of recurrent scleritis. METHODS: A total of 15 patients with scleritis (12 anterior, 3 pan) underwent IMMP injection deep into the thigh. Thirteen patients were already being treated with oral non-steroidal anti-inflammatory drugs, oral prednisolone, an oral immunosuppressive agent, or a combination of these drugs. A second IMMP injection was given to nine patients, making a total of 24 injections. Follow-up ranged from 4 to 18 months. RESULTS: There was a documented improvement in scleritis after 21/24 (87.3%) injections with a mean duration of improvement of 5.7 months. No patient required the introduction of oral corticosteroid or immunosuppressive agent, and only one patient required an increase in methotrexate to control the disease. No systemic, injection site, or ocular side effects were noted. CONCLUSIONS: Deep IMMP is a safe and effective treatment for scleritis. It ensures compliance, avoids the systemic side effects of oral corticosteroids, and is easily repeatable in the outpatient setting.


Assuntos
Glucocorticoides/uso terapêutico , Metilprednisolona/uso terapêutico , Esclerite/tratamento farmacológico , Adulto , Idoso , Feminino , Humanos , Injeções Intramusculares , Masculino , Pessoa de Meia-Idade , Recidiva , Resultado do Tratamento
19.
Int J Gen Med ; 7: 339-43, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25061334

RESUMO

OBJECTIVE: Anticonvulsants are increasingly being used in the symptomatic management of several neuropathic pain disorders. The present observational study was designed to evaluate the efficacy, tolerability, and quality of life (QoL) of carbamazepine use for 12 weeks in patients with painful diabetic neuropathy, in Pakistan. METHODS: This was a 12-week, multicenter, open-label, uncontrolled trial in adult type 2 diabetic patients (aged 18-65 years) suffering from clinically confirmed neuropathic pain (Douleur Neuropathique en 4 [DN4] score ≥4). Change in neuropathic pain at week 12 compared with baseline was assessed using the Brief Pain Inventory Scale-Short Form (pain severity score and pain interference score). QoL was determined by the American Chronic Pain Association QoL scale. Safety was assessed based on patient reported adverse events (AEs) and serious AEs. RESULTS: Of the total 500 screened patients, 452 enrolled and completed the study. The mean (± standard deviation [SD]) pain interference score decreased from 4.5±2.0 at baseline to 3.1±1.9 at week 12 (P<0.001). The mean (± SD) pain severity score decreased from 5.8±2.0 at baseline to 3.6±2.2 at week 12 (P<0.001). There was a decrease of ≥30% in the pain severity score between visits. The mean (± SD) QoL scale score improved from 5.9±1.6 at baseline to 8.0±1.7 at week 12. A total of ten (2.2%) patients reported AEs during the study period. No patient discontinued the study due to AEs. CONCLUSION: In this real-life experience study, carbamazepine, when prescribed for 12 weeks to adult diabetic patients suffering from neuropathic pain, showed pain-relief effect, with reduced mean pain severity and mean pain interference scores and with improved QoL and good tolerability profile.

20.
Comput Biol Chem ; 53PB: 277-291, 2014 12.
Artigo em Inglês | MEDLINE | ID: mdl-25462335

RESUMO

Dengue virus can ignite both protective and pathogenic responses in human. The pathogenesis is related with modified functioning of our immune system during infection. Pattern recognition receptors like Toll like receptor 3 is vital for the induction of innate immunity in case of Dengue infection. Toll like receptor 3 induces TRIF mediated activation of Type 1 interferons and Fc receptor mediated induction of cytokines. Interferons have been related with clearance of Dengue virus but it has adopted modified regulatory mechanisms to counter this effect. SOCS protein is also induced due to the interferon and cytokine mediated signalling which can subsequently play its part in the regulation of interferon and cytokine production. Our hypothesis in this study relates the pathogenesis of Dengue virus with the SOCS mediated inhibition of our innate immunity. We used the qualitative formalism of René Thomas to model the biological regulatory network of Toll like receptor 3 mediated signalling pathway in an association with pathogenesis of dengue. Logical parameters for the qualitative modelling were inferred using a model checking approach implemented in SMBioNet. A linear hybrid model, parametric linear hybrid automaton, was constructed to incorporate the activation and inhibition time delays in the qualitative model. The qualitative model captured all the possible expression dynamics of the proteins in the form of paths, some of which were observed as abstract cycles (representing homoeostasis) and diverging paths towards stable states. The analysis of the qualitative model highlighted the importance of SOCS protein in elevating propagation of dengue virus through inhibition of type 1 interferons. Detailed qualitative analysis of regulatory network endorses our hypothesis that elevated levels of cytokine subsequently induce SOCS expression which in turn results into the continuous down-regulation of Toll like receptor 3 and interferon. This may result into the Dengue pathogenesis during the stage of immunosuppression. Further analysis with HyTech (HYbrid TECHnology) tool provided us with the real-time constraints (delay constraints) of the proteins involved in the cyclic paths of the regulatory network backing the evidence provided by the qualitative analysis. The HyTech results also suggest that the role of SOCS is vital in homoeostasis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA