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1.
Small ; : e2407160, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39390843

RESUMO

Water polluted by toxic chemicals due to waste from chemical/pharmaceuticals and harmful microbes such as E. Coli bacteria causes several fatal diseases; and therefore, water filtration is crucial for accessing clean and safe water necessary for good health. Conventional water filtration technologies include activated carbon filters, reverse osmosis, and ultrafiltration. However, they face several challenges, including high energy consumption, fouling, limited selectivity, inefficiencies in removing certain contaminants, dimensional control of pores, and structural/chemical changes at higher thermal conditions and upon prolonged usage of water filter. Recently, the advent of 2D materials such as graphene, BN, MoS2, MXenes, and so on opens new avenues for advanced water filtration systems. This review delves into the nanoarchitectonics of 2D materials for water filtration applications. The current state of water filtration technologies is explored, the inherent challenges they face are outlines, and the unique properties and advantages of 2D materials are highlighted. Furthermore, the scope of this review is discussed, which encompasses the synthesis, characterization, and application of various 2D materials in water filtration, providing insights into future research directions and potential industrial applications.

2.
J Water Health ; 21(6): 663-675, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37387334

RESUMO

Artisanal and small-scale gold mining (ASGM) activity in Way Ratai River produces heavy metal wastes; therefore, further information regarding heavy metal concentrations in the water was needed, especially in plankton samples. Furthermore, the determination of plankton diversity was also carried out in the waters of Way Ratai to determine the bioconcentration factor (BCF). Eight sampling sites were chosen along the river reaching the coast of Way Ratai. The research was conducted in November 2020 and March 2021. Ten heavy metals, Ag, Cd, Co, Cr, Cu, Fe, Mn, Pb, and Zn that are commonly found in mining areas, were determined in the water and plankton samples by using ICP-OES. The results indicated that the highest concentration found was Fe in plankton samples (0.725 mg/L in the river and 1.294 mg/L on the coast). Meanwhile, contents of Cd, Cu, Fe, Mn, and Zn in the river exceeded the predetermined water quality standards, while Ag and Pb metals were not detected. The Cd, Cr, Cu, Pb, and Zn content in seawater also exceeded quality standards. The highest BCF value (12.96) was found for Fe at station G, whereas the lowest BCF value (0.13) was found for Ag at stations G and H.


Assuntos
Baías , Metais Pesados , Indonésia , Cádmio , Chumbo , Plâncton
3.
Rev Neurol (Paris) ; 179(4): 368-372, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36336489

RESUMO

The objectives were to analyze changes from 2012 to 2017 in different management times of stroke patients included in the Aquitaine stroke Observatory (ObA2). The studied times (onset-to-needle time-ONT, onset-to-door time-ODT, door-to-imaging time-DIT, door-to-needle time-DNT and imaging-to-needle time-INT) were described as median, interquartile ranges and proportion of patients within the recommended median time goals (ODT under 4hours, DIT within 20min; for thrombolyzed patients, DIT under 20min and a ONT under 4:30) to be compared with an objective of 50% of patients within said time goal. Globally, ODT was 160min, with 43.6% to 59.6% of patients within the ODT goal along the study period. With no improvement over time, the proportion of patients within the DIT goal stayed stable and at a low level (range: 5.5-7.0%) for all patients, decreasing from 25.2% to 11.4% for thrombolyzed patients. The proportion of thrombolyzed patients within the DNT goal varied from 15.1% to 30.3% during study period. These results highlight the urgent need for action to improve in-hospital management of stroke patients, focusing on delays between admission and imaging.


Assuntos
Hospitalização , Acidente Vascular Cerebral , Humanos , Estudos de Coortes , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/terapia , Hospitais
4.
Saudi Pharm J ; 30(4): 329-336, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35527831

RESUMO

Background: Medication error is a preventable adverse effect of medical care, whether or not it is evident or harmful to the patient. Disclosure of medication errors and improvement of patient safety are inexorably related, and they provide one of the strongest reasons to report and disclose errors, including near misses in which no harm comes to the patient. This study aimed to identify medication errors at the southern province of Saudi Arabia. Methods: A cross-sectional retrospective study was conducted by reviewing all medical records in the King Khaled Hospital in Najran, Saudi Arabia. Medication errors related information were extracted from the electronic medical system for the duration between 2018 and 2020. Results: During the study period of 2018 to 2020, a total of 4860 medication errors were identified. More than half of the reported medication errors (66.9%) were linked to ordering, prescribing, or transcribing medications. The most commonly reported medication errors connected to ordering/prescribing/transcribing were inappropriate dosage, dosage units, and therapeutic duplication of medication. The most commonly reported medication errors linked to administration were missing documentation during administration, not performing independent double-checks during the administration of high alert medications, and the administration of look-alike sound-alike (LASA) medications. The intensive care unit (ICU), female medical ward, and male medical ward were the most commonly reported locations for medication errors. Pharmacists detected more than half of the reported medication errors. Physicians were found to be responsible for 66.0% of reported medication errors, followed by nurses. Conclusion: Medication errors are common in hospital settings in Saudi Arabia's southern provinces. Efforts should be made to improve drug ordering, prescribing, and transcription in hospital settings. To guarantee optimum practices, the entire medical team should take responsibility for the patient's optimal medication administration.

5.
Development ; 144(13): 2381-2391, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28526751

RESUMO

For decades, it was commonly thought that the bilateral heart fields in the early embryo fold directly towards the midline, where they meet and fuse to create the primitive heart tube. Recent studies have challenged this view, however, suggesting that the heart fields fold diagonally. As early foregut and heart tube morphogenesis are intimately related, this finding also raises questions concerning the traditional view of foregut formation. Here, we combine experiments on chick embryos with computational modeling to explore a new hypothesis for the physical mechanisms of heart tube and foregut formation. According to our hypothesis, differential anisotropic growth between mesoderm and endoderm drives diagonal folding. Then, active contraction along the anterior intestinal portal generates tension to elongate the foregut and heart tube. We test this hypothesis using biochemical perturbations of cell proliferation and contractility, as well as computational modeling based on nonlinear elasticity theory including growth and contraction. The present results generally support the view that differential growth and actomyosin contraction drive formation of the foregut and heart tube in the early chick embryo.


Assuntos
Actomiosina/metabolismo , Sistema Digestório/embriologia , Coração/embriologia , Modelos Biológicos , Organogênese , Animais , Proliferação de Células , Embrião de Galinha , Simulação por Computador , Análise de Elementos Finitos
6.
Vascular ; 28(4): 457-464, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32212917

RESUMO

OBJECTIVE: Thromboangiitis obliterans is a nonatherosclerotic occlusive disease, affecting small to moderate sized arteries of the upper and lower extremities, leading to progressive inflammation and clot formation. However, the role of humoral and cell-mediated immunity in the development of this disease has not been clearly identified. The present study was intended to investigate the humoral and cellular immune response in patients with Buerger's disease with different disease severity. METHODS: In an observational study, 80 male patients with Buerger's disease were included and categorized into three groups (mild, moderate, and severe) based on clinical manifestations. After blood sampling, cellular phenotypes were determined, and erythrocyte sedimentation rate, immunoglobulins (Ig) A, M, G, and E, as well as C3 and C4 components of the complement system and complement hemolytic activity (CH50) were measured. RESULTS: The mean age of the patient was 42.85 ± 8.39 years. Pulse abnormality, cold intolerance, and claudication were the most common symptoms. Eleven (13.75%), 46 (57.50%), and 23 (28.75%) patients had mild, moderate, and severe symptoms. Regression analyses showed that the presence of severe symptoms was significantly associated with elevated erythrocyte sedimentation rate and C4 levels (p < 0.05). CONCLUSION: Buerger's disease in severe cases was associated with increased erythrocyte sedimentation rate and abnormal C4 levels. The alterations in these inflammatory biomarkers might be due to a secondary inflammatory response to the presence of ulcer or gangrene and the inflammatory process in patients with severe symptoms.


Assuntos
Complemento C4/análise , Eritrócitos/imunologia , Imunidade Celular , Imunidade Humoral , Tromboangiite Obliterante/imunologia , Adulto , Biomarcadores/sangue , Sedimentação Sanguínea , Humanos , Masculino , Pessoa de Meia-Idade , Nefelometria e Turbidimetria , Valor Preditivo dos Testes , Sistema de Registros , Índice de Gravidade de Doença , Tromboangiite Obliterante/sangue , Tromboangiite Obliterante/fisiopatologia , Regulação para Cima
7.
Dermatol Online J ; 26(12)2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33423423

RESUMO

Palisaded encapsulated neuroma is a rare, benign neural tumor. The involvement of the glans penis is rare; few cases have been reported. We present a 52-year-old man with a five-month course of a solitary painless lesion of the glans penis. Full excision of the nodule was performed. Histopathological and immunohistochemical analyses and examination was consistent with a palisaded encapsulated neuroma. We describe one of a few existing cases of this kind of tumor in the glans penis.


Assuntos
Neuroma/patologia , Neoplasias Penianas/patologia , Pênis/patologia , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Neuroma/diagnóstico , Neoplasias Penianas/diagnóstico
8.
J Endocrinol Invest ; 40(7): 741-744, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28239763

RESUMO

BACKGROUND: Even though patients with type 1 diabetes mellitus (T1DM) are exempted from fasting, the vast majority elect to fast against the advice of their healthcare providers. We have previously reported the incidence of wide fluctuations in blood glucose (BG) along with "unrecognized" severe hypoglycemia during Ramadan fasting in adolescents with T1DM. This report compares the continuous glucose monitoring (CGM) data during fasting in adolescents with T1DM according to their Pre-Ramadan diabetes control. METHODS: Children and adolescents with T1DM who intended to fast the month of Ramadan were asked to wear the CGM during fasting for a minimum of 3 days. Hypoglycemia, hyperglycemia, and severe hyperglycemia were identified as BG <70 mg/dL (3.9 mmol/L), BG 201-300 mg/dL (11.2-16.7 mmol/L), or BG >300 mg/dL (16.7 mmol/L) respectively, while normoglycemia was identified as BG 70-200 mg/dL (3.9-11.1 mmol/L). Patients were categorized as well-controlled (Group 1) and poorly controlled (Group 2) if the pre-fasting HbA1C was ≤8% (64 mmol/mol) and >8%, respectively. We compared the mean BG and the percentages of time spent in hypoglycemia, hyperglycemia, and severe hyperglycemia between the two groups using Chi-square (significant difference when P value was <0.05). RESULTS: A total of 21 patients were enrolled (15 females), age 15 ± 4 years, duration of diabetes 6 ± 3 years, and HbA1C 8.5 ± 1.0% (70 mmol/mol). There were 7 subjects in Group 1, mean HbA1C 7.5 ± 0.4, and 14 subjects in Group 2, mean HbA1C 9.1 ± 0.9. The mean ± SD BG was 174 ± 76 mg/dL versus 199 ± 98, (P < 0.05) in Group 1 and Group 2, respectively. The percentages of hypoglycemia, hyperglycemia, and severe hyperglycemia were significantly higher in Group 2, while there was a higher percentage of normoglycemia in Group 1. The overall durations of hypoglycemia, hyperglycemia, and severe hyperglycemia in Group 2 were longer by 30, 14, and 135%, respectively, than those in Group 1. CONCLUSIONS: Glycemic control before Ramadan in adolescents with T1 DM appears to correlate with blood glucose profile during Ramadan fasting. Our data suggest that optimal glycemic control before Ramadan may reduce the potential risks associated with fasting and minimize glucose fluctuation.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 1/fisiopatologia , Jejum/fisiologia , Hiperglicemia/epidemiologia , Hipoglicemia/epidemiologia , Hipoglicemiantes/administração & dosagem , Islamismo , Adolescente , Diabetes Mellitus Tipo 1/tratamento farmacológico , Feminino , Hemoglobinas Glicadas/análise , Humanos , Hiperglicemia/induzido quimicamente , Hipoglicemia/induzido quimicamente , Masculino , Prevalência , Emirados Árabes Unidos/epidemiologia
9.
Mater Struct ; 502017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28082830

RESUMO

This paper presents a one-dimensional finite difference model that is developed to describe the freeze-thaw behavior of an air-entrained mortar containing deicing salt solution. A phenomenological model is used to predict the temperature and the heat flow for mortar specimens during cooling and heating. Phase transformations associated with the freezing/melting of water/ice or transition of the eutectic solution from liquid to solid are included in this phenomenological model. The lever rule is used to calculate the quantity of solution that undergoes the phase transformation, thereby simulating the energy released/absorbed during phase transformation. Undercooling and pore size effects are considered in the numerical model. To investigate the effect of pore size distribution, this distribution is considered using the Gibbs-Thomson equation in a saturated mortar specimen. For an air-entrained mortar, the impact of considering pore size (and curvature) on freezing was relatively insignificant; however the impact of pore size is much more significant during melting. The fluid inside pores smaller than 5 nm (i.e., gel pores) has a relatively small contribution in the macroscopic freeze-thaw behavior of mortar specimens within the temperature range used in this study (i.e., +24 °C to -35 °C), and can therefore be neglected for the macroscopic freeze-thaw simulations. A heat sink term is utilized to simulate the heat dissipation during phase transformations. Data from experiments performed using a low-temperature longitudinal guarded comparative calorimeter (LGCC) on mortar specimens fully saturated with various concentration NaCl solutions or partially saturated with water is compared to the numerical results and a promising agreement is generally obtained.

10.
Apoptosis ; 21(9): 997-1007, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27343126

RESUMO

Calcitriol is the metabolically active form of Vitamin D and is known to kill cancer cells. Using the rat model of DEN induced hepatocellular carcinoma we show that there is a marked increase in cellular levels of copper in hepatocellular carcinoma and that calcitriol-copper interaction leads to reactive oxygen species mediated DNA breakage selectively in hepatocellular carcinoma cells. In vivo studies show that calcitriol selectively induces severe fluctuations in cellular enzymatic and non enzymatic scavengers of reactive oxygen species in the malignant tissue. Lipid peroxidation, a well established marker of oxidative stress, was found to increase, and substantial cellular DNA breakage was observed. We propose that calcitriol is a proxidant in the cellular milieu of hepatocellular carcinoma cells, and this copper mediated prooxidant action of calcitriol causes selective DNA breakage in malignant cells, while sparing normal (non malignant) cells.


Assuntos
Antioxidantes/metabolismo , Calcitriol/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Cobre/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose , Carcinoma Hepatocelular/fisiopatologia , Dano ao DNA , Humanos , Peroxidação de Lipídeos , Neoplasias Hepáticas/fisiopatologia , Masculino , Estresse Oxidativo , Ratos
11.
Cerebellum ; 15(6): 755-766, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-26607150

RESUMO

Recent studies have found that in the cerebellum, the δ2 glutamate receptor (GluRδ2) plays a key role in regulating the differentiation of parallel fiber-Purkinje synapses and mediating key physiological functions in the granule cell-Purkinje cell circuit. In the hotfoot mutant or GluRδ2 knockout mice, the absence of GluRδ2 expression results in impaired motor-related tasks, ataxia, and disruption of long-term depression at parallel fiber-Purkinje cell synapses. The goal of this study was to determine the long-term consequences of deletion of GluRδ2 expression in the hotfoot mutant (GluRδ2 ho/ho ) on Purkinje and granule cell survival and Purkinje cell dendritic differentiation. Quantitative estimates of Purkinje and granule cell numbers in 3-, 12-, and 20-month-old hotfoot mutants and wild-type controls showed that Purkinje cell numbers are within control values at 3 and 12 months in the hotfoot mutant but reduced by 20 % at 20 months compared with controls. In contrast, the number of granule cells is significantly reduced from 3 months onwards in GluRδ2 ho/ho mutant mice compared to wild-type controls. Although the overall structure of Purkinje cell dendrites does not appear to be altered, there is a significant 27 % reduction in the cross-sectional area of Purkinje cell dendritic trees in the 20-month-old GluRδ2 ho/ho mutants. The interpretation of the results is that the GluRδ2 receptor plays an important role in the long-term organization of the granule-Purkinje cell circuit through its involvement in the regulation of parallel fiber-Purkinje cell synaptogenesis and in the normal functioning of this critical cerebellar circuit.


Assuntos
Cerebelo/metabolismo , Cerebelo/patologia , Neurônios/metabolismo , Neurônios/patologia , Receptores de Glutamato/metabolismo , Envelhecimento/metabolismo , Envelhecimento/patologia , Análise de Variância , Animais , Calbindinas/metabolismo , Contagem de Células , Morte Celular/fisiologia , Tamanho Celular , Sobrevivência Celular/fisiologia , Cerebelo/crescimento & desenvolvimento , Feminino , Imuno-Histoquímica , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fotomicrografia , Receptores de Glutamato/genética
12.
Crit Rev Food Sci Nutr ; 56(9): 1501-18, 2016 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-25365584

RESUMO

Neoplastic conditions associated with gastrointestinal (GI) tract are common worldwide with colorectal cancer alone accounting for the third leading rate of cancer incidence. Other GI malignancies such as esophageal carcinoma have shown an increasing trend in the last few years. The poor survival statistics of these fatal cancer diseases highlight the need for multiple alternative treatment options along with effective prophylactic strategies. Worldwide geographical variation in cancer incidence indicates a correlation between dietary habits and cancer risk. Epidemiological studies have suggested that populations with high intake of certain dietary agents in their regular meals have lower cancer rates. Thus, an impressive embodiment of evidence supports the concept that dietary factors are key modulators of cancer including those of GI origin. Preclinical studies on animal models of carcinogenesis have reflected the pharmacological significance of certain dietary agents called as nutraceuticals in the chemoprevention of GI neoplasia. These include stilbenes (from red grapes and red wine), isoflavones (from soy), carotenoids (from tomatoes), curcuminoids (from spice turmeric), catechins (from green tea), and various other small plant metabolites (from fruits, vegetables, and cereals). Pleiotropic action mechanisms have been reported for these diet-derived chemopreventive agents to retard, block, or reverse carcinogenesis. This review presents a prophylactic approach to primary prevention of GI cancers by highlighting the translational potential of plant-derived nutraceuticals from epidemiological, laboratory, and clinical studies, for the better management of these cancers through consumption of nutraceutical rich diets and their intervention in cancer therapeutics.


Assuntos
Anticarcinógenos , Dieta , Suplementos Nutricionais , Neoplasias Gastrointestinais/prevenção & controle , Animais , Carotenoides , Curcumina , Neoplasias Gastrointestinais/tratamento farmacológico , Neoplasias Gastrointestinais/epidemiologia , Humanos , Isoflavonas , Estilbenos
13.
J Vasc Surg ; 62(1): 135-42, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25827966

RESUMO

OBJECTIVE: Hemodialysis access-induced distal ischemia (HAIDI) can be classified as acute (on the first postoperative day), subacute (≤1 month), or chronic (>1 month), based on the time of onset after access creation. The diagnosis is mainly clinical. However, performing additional tests is beneficial in further assessment of patients. The purpose of this study was to evaluate the use of finger pressure and oxygen saturation measurements for the diagnosis of chronic HAIDI. METHODS: A total of 20 patients with chronic HAIDI (cases) and 40 asymptomatic hemodialysis patients (controls) were matched for age, sex, etiology of end-stage renal disease, and type of arteriovenous access. Basal digital pressure (BDP), digital pressure during manual compression of access, digital brachial index (DBI), change in digital pressure with access compression (CDP), digital pressure of the contralateral side, and bilateral oxygen saturation (O2 Sat) were measured in all patients. RESULTS: In the case group, compression of the arteriovenous fistula (AVF) increased mean BDP from 61 ± 26 to 118 ± 28 mm Hg (P < .001), which failed to reach the non-AVF side mean digital pressure of 151 ± 25 mm Hg (P < .001). In addition, O2 Sat of the AVF side was significantly lower than the contralateral side (92.9% ± 2.1% vs 95.6% ± 1.4%; P = .001). Among the controls, manual AVF compression raised the mean BDP from 114 ± 36 mm Hg to 133 ± 29 mm Hg (P < .001), which was still significantly lower than the contralateral side mean digital pressure of 141 ± 30 mm Hg (P = .002). In addition, O2 Sat values of the two sides were different (96.7% ± 2.1% vs 97.1% ± 1.9%; P = .01). Comparing the cases and controls, the mean BDP (61 ± 26 mm Hg vs 114 ± 36 mm Hg; P < .001), DBI (0.44 ± 0.16 vs 0.82 ± 0.19; P < .001), and O2 Sat (92.9% ± 2.1% vs 96.7% ± 2.1%; P < .001) were significantly lower and CDP (57 ± 24 mm Hg vs 19 ± 17 mm Hg; P < .001) was significantly higher in the cases than in the controls. The optimal discriminatory thresholds of 80 mm Hg for BDP, 0.7 for DBI, 40 mm Hg for CDP, and 94% for O2 Sat were determined. CONCLUSIONS: Digital pressure and O2 Sat measurements are useful additional methods to assist in the clinical evaluation of hemodialysis patients with access-related hand ischemia. BDP <80 mm Hg, DBI <0.7, CDP >40 mm Hg, and O2 Sat <94% are associated with chronic HAIDI.


Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Determinação da Pressão Arterial , Pressão Sanguínea , Mãos/irrigação sanguínea , Isquemia/diagnóstico , Falência Renal Crônica/terapia , Oximetria , Oxigênio/sangue , Diálise Renal , Adulto , Biomarcadores/sangue , Determinação da Pressão Arterial/métodos , Estudos de Casos e Controles , Feminino , Humanos , Isquemia/sangue , Isquemia/fisiopatologia , Falência Renal Crônica/diagnóstico , Masculino , Pessoa de Meia-Idade , Oximetria/métodos , Fotopletismografia , Valor Preditivo dos Testes , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
14.
Tumour Biol ; 36(11): 8861-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26069106

RESUMO

We have earlier elucidated a pathway for the anticancer action of plant polyphenolic compounds against malignant cells involving mobilisation of endogenous copper ions and the consequent prooxidant action. To further confirm our hypothesis in vivo, we induced hepatocellular carcinoma (HCC) in rats by diethylnitrosamine (DEN). We show that in such carcinoma cells, there is a progressive elevation in copper levels at various intervals after DEN administration. Concurrently with increasing copper levels, epigallocatechin-3-gallate (EGCG; a potent anticancer plant polyphenol found in green tea) mediated DNA breakage in malignant cells is also increased. The cell membrane permeable copper chelator neocuproine inhibited the EGCG-mediated cellular DNA degradation, whereas the membrane impermeable chelator bathocuproine was ineffective. Iron and zinc specific chelators desferoxamine mesylate and histidine, respectively, were also ineffective in inhibiting EGCG mediated DNA breakage. Through the use of specific scavengers, the mechanism of DNA breakage was determined to be mediated by reactive oxygen species. In summary, we provide an in vivo evidence of accumulating copper in hepatocellular carcinoma that is targeted by EGCG, leading to its anticancer role in a prooxidant manner. Our findings confirm a novel mechanism of anticancer activity of EGCG in particular and plant derived nutraceuticals in general.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Catequina/análogos & derivados , Cobre/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Animais , Carcinoma Hepatocelular/induzido quimicamente , Carcinoma Hepatocelular/patologia , Catequina/administração & dosagem , Catequina/química , Permeabilidade da Membrana Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Dietilnitrosamina/toxicidade , Sequestradores de Radicais Livres/metabolismo , Humanos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/patologia , Estresse Oxidativo/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/administração & dosagem , Chá/química
15.
Arch Biochem Biophys ; 580: 31-40, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26142371

RESUMO

Epidemiological studies suggest that dietary consumption of plant polyphenols is related to a lower incidence of various cancers. Among these compounds catechins (present in green tea and other beverages) are considered to be potent inducers of apoptosis and cytotoxicity to cancer cells. Thus these compounds can be used as leads to synthesize novel anticancer drugs with greater bioavailability. In view of this in this paper we have examined the chemical basis of cytotoxicity of catechins by studying the structure-activity relationship between catechin (C), epicatechin (EC), epigallocatechin (EGC) and epigallocatechin-3-gallate (EGCG). Using single cell alkaline gel electrophoresis (comet assay) we have established the relative efficiency of cellular DNA breakage as EGCG>EGC>EC>C. We also show that cellular DNA breakage is the result of mobilization of copper ions bound to chromatin and the generation of reactive oxygen species. Further the relative DNA binding affinity order was confirmed using molecular docking and thermodynamic studies by studying the interaction of catechins with calf thymus DNA. The results suggest that the synthesis of any novel anti cancer molecule based on the structure of catechins should have as many galloyl moieties as possible resulting in an increased number of hydroxyl groups that may facilitate the binding of the molecule to cellular DNA.


Assuntos
Catequina/análogos & derivados , Catequina/química , Cobre/química , Linfócitos/química , Animais , Catequina/farmacologia , Cátions Monovalentes , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Cromatina/química , Cromatina/efeitos dos fármacos , Ensaio Cometa , DNA/química , Fragmentação do DNA/efeitos dos fármacos , Humanos , Linfócitos/efeitos dos fármacos , Simulação de Acoplamento Molecular , Oxirredução , Cultura Primária de Células , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade , Termodinâmica
18.
Adv Exp Med Biol ; 822: 37-51, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25416975

RESUMO

There are reports in scientific literature that the concentration of copper ions in Parkinsonian brain is at a level that could promote oxidative DNA damage. The possibility of copper chelation by antioxidants excited us to explore the generation of reactive oxygen species (ROS) and DNA damage by the interaction of L-DOPA with Cu(II) ions. In the present manuscript, L-DOPA was tested for its ability to bind with Cu(II) and reduce it to Cu(I). The generation of ROS, such as superoxide anion (O(2)(-)) and hydroxyl radical (OH(•)), was also ascertained. As a result of L-DOPA and Cu(II) interaction, the generation of O(2)(-) was found to be increased in a time-dependent manner. Moreover, the formation of OH(•) was also found to be enhanced with increasing concentrations of L-DOPA. Furthermore, Comet assay results clearly showed significantly higher cellular DNA breakage in lymphocytes treated with L-DOPA and Cu(II) as compared to those that were treated with L-DOPA alone. However, such DNA degradation was inhibited to a significant extent by scavengers of ROS and neocuproine, a membrane permeable Cu(I)-specific sequestering agent. These findings demonstrate that L-DOPA exhibits a pro-oxidant activity in the presence of copper ions.


Assuntos
Cobre/metabolismo , Quebras de DNA , Levodopa/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Antiparkinsonianos/química , Antiparkinsonianos/metabolismo , Antiparkinsonianos/farmacologia , Quelantes/farmacologia , Ensaio Cometa , Cobre/química , Cobre/farmacologia , Humanos , Radical Hidroxila/química , Radical Hidroxila/metabolismo , Levodopa/química , Levodopa/farmacologia , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Síndromes Neurotóxicas/metabolismo , Síndromes Neurotóxicas/patologia , Oxirredução/efeitos dos fármacos , Fenantrolinas/farmacologia , Espécies Reativas de Oxigênio/química , Superóxidos/química , Superóxidos/metabolismo
19.
J Biomech Eng ; 136(4)2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24384581

RESUMO

Osteoporosis-related vertebral fractures represent a major health problem in elderly populations. Such fractures can often only be diagnosed after a substantial deformation history of the vertebral body. Therefore, it remains a challenge for clinicians to distinguish between stable and progressive potentially harmful fractures. Accordingly, novel criteria for selection of the appropriate conservative or surgical treatment are urgently needed. Computer tomography-based finite element analysis is an increasingly accepted method to predict the quasi-static vertebral strength and to follow up this small strain property longitudinally in time. A recent development in constitutive modeling allows us to simulate strain localization and densification in trabecular bone under large compressive strains without mesh dependence. The aim of this work was to validate this recently developed constitutive model of trabecular bone for the prediction of strain localization and densification in the human vertebral body subjected to large compressive deformation. A custom-made stepwise loading device mounted in a high resolution peripheral computer tomography system was used to describe the progressive collapse of 13 human vertebrae under axial compression. Continuum finite element analyses of the 13 compression tests were realized and the zones of high volumetric strain were compared with the experiments. A fair qualitative correspondence of the strain localization zone between the experiment and finite element analysis was achieved in 9 out of 13 tests and significant correlations of the volumetric strains were obtained throughout the range of applied axial compression. Interestingly, the stepwise propagating localization zones in trabecular bone converged to the buckling locations in the cortical shell. While the adopted continuum finite element approach still suffers from several limitations, these encouraging preliminary results towards the prediction of extended vertebral collapse may help in assessing fracture stability in future work.


Assuntos
Força Compressiva , Análise de Elementos Finitos , Fraturas Ósseas/fisiopatologia , Coluna Vertebral/fisiopatologia , Estresse Mecânico , Idoso , Idoso de 80 Anos ou mais , Densidade Óssea , Feminino , Fraturas Ósseas/diagnóstico por imagem , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X
20.
J Trop Pediatr ; 60(6): 476-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25213739

RESUMO

Basidiobolomycosis is a rare disease due to fungus Basidiobolus ranarum, an environmental saprophyte that is found worldwide, though mainly reported in the tropical and subtropical regions. Basidiobolomycosis is an unusual fungal skin infection, rarely involves the gastrointestinal (GI) tract. Most of the cases of paediatric GI basidiobolomycosis (GIB) were reported from the southern region of Saudi Arabia. We report an 11-year-old Saudi boy. He presented with a huge right lower quadrant abdominal mass and marked eosinophilia. Abdominal computed tomography scan revealed a large caecal mass. A biopsy was taken and it showed transmural granulomatous inflammation. A diagnosis of GIB was confirmed by specific features in histopathology. Most of the reported paediatric cases with GIB required adjuvant therapy of antifungal and surgical resection. In our case, treatment with voriconazole alone for 1 year was successful with complete recovery and with no recurrence after a year of discontinuing the treatment.


Assuntos
Antifúngicos/uso terapêutico , Entomophthorales/efeitos dos fármacos , Voriconazol/uso terapêutico , Zigomicose/tratamento farmacológico , Biópsia , Criança , Eosinofilia/etiologia , Humanos , Masculino , Arábia Saudita , Resultado do Tratamento , Zigomicose/diagnóstico
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