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1.
Med J Armed Forces India ; 78(Suppl 1): S145-S151, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36147398

RESUMO

Background: Osteomyelitis of the jawbone is mostly secondary to radiation exposure or bone remodelling drugs, with the mandible being commonly involved. Maxillary osteomyelitis risk is low owing to its high vascularity. This study was undertaken to evaluate risk factors, presentation, management and outcomes of maxillary osteomyelitis caused due to reasons other than irradiation and bone remodelling drugs. Methods: Patient records diagnosed with maxillary osteomyelitis were evaluated for demographic details, risk factors, clinical presentation, radiological features, treatment performed and outcomes. Results: In 38 patients with non-irradiated and non-drug-induced osteomyelitis, 13 involved the maxilla, seven were localized to the posterior maxilla and 10 showed paranasal sinus involvement. Dissemination to the cavernous sinus and cerebral spread was seen in one. Clinical findings included oroantral communication, pain and draining sinus. Imaging showed diffuse bone destruction areas with or without evidence of bony sequestrum. The most common systemic risk factor was diabetes mellitus. Maxillary osteomyelitis was associated with tooth extraction in eight cases. Surgical management included debridement, sequestrectomy, functional endoscopic sinus surgery, maxillectomy and reconstruction of soft tissue defect with local and regional flaps. Complete recovery was seen in 11 patients. Mortality was seen in two patients with mucormycosis having disseminated infection. Conclusion: Compared with previous literature, a relatively higher ratio of maxillary involvement was reported. Diabetes mellitus was the most common risk factor, followed by osteopetrosis and tooth extraction. Osteomyelitis secondary to mucormycosis in immunocompetent patients was relatively localized and gave favourable response to management compared with patients with diabetes mellitus.

2.
Chembiochem ; 21(6): 825-835, 2020 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-31553819

RESUMO

Antibiotics are known to promote bacterial formation of enhanced biofilms, the mechanism of which is not well understood. Here, using biolayer interferometry, we have shown that bacterial cultures containing antibiotics that target cell walls cause biomass deposition on surfaces over time with a linear profile rather than the Langmuir-like profiles exhibited by bacterial adherence in the absence of antibiotics. We observed about three times the initial rate and 12 times the final biomass deposition on surfaces for cultures containing carbenicillin than without. Unexpectedly, in the presence of antibiotics, the rate of biomass deposition inversely correlated with bacterial densities from different stages of a culture. Detailed studies revealed that carbenicillin caused faster growth of filaments that were seeded on surfaces from young bacteria (from lag phase) than those from high-density fast-growing bacteria, with rates of filament elongation of about 0.58 and 0.13 µm min-1 , respectively. With surfaces that do not support bacterial adherence, few filaments were observed even in solution. These filaments aggregated in solution and formed increased amounts of biofilms on surfaces. These results reveal the lifestyle of antibiotic-induced filamentous bacteria, as well as one way in which the antibiotics promote biofilm formation.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Carbenicilina/farmacologia , Parede Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Escherichia coli/citologia , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/citologia , Propriedades de Superfície
3.
J Maxillofac Oral Surg ; 23(1): 204-209, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38312952

RESUMO

Background: Internal derangement (ID) of temporomandibular joint (TMJ) is a common temporomandibular disorder (TMD) which causes hypomobility of the joint. Minimally invasive treatment modality like arthrocentesis is used as first-line of management having low morbidity and high efficacy. This prospective randomized comparative study was carried to compare the efficacy of intra-articular injection with sodium hyaluronate (SH) and triamcinolone acetonide (TA) after arthrocentesis in ID of TMJ. Materials and Methods: A total 40 patients diagnosed with ID (stage 1-4) were included in the study and randomly divided in two groups. Twenty patients (group A) received intra-articular injection of SH while 20 patients (group B) received intra-articular injection of TA, after arthrocentesis. The clinical parameters of pain (VAS), Maximum mouth opening (MMO) (mm) and clicking sound (present/absent) were evaluated pre-operatively and at seventh day, 1 month and 3 months post-operatively. Results: There was statistically significant improvement in pain scores in both the groups at all time intervals with SH being superior (p value 0.0086). All the patients showed improved mouth opening at all time intervals, TA being superior but statistically insignificant (p value 0.59). There was reduction in the clicking sound in both the groups which was statistically insignificant at all time intervals. Conclusions: Arthrocentesis followed by intra-articular injection with SH is superior to TA in terms of pain reduction, while TA showed superiority in terms of improved mouth opening.

4.
J Craniofac Surg ; 24(4): e432-4, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23851893

RESUMO

Numbness and ulceration of the face, particularly erosion of ala of the nose, sometimes occur after sensory denervation in the territory of the divisions of the trigeminal nerve. The incidence is uncertain and usually follows surgical treatments for trigeminal neuralgia. Such condition is known as trigeminal trophic syndrome (TTS), although some authors believe it to be a special form of dermatitis artefacta. Trigeminal trophic syndrome most commonly affects adults, after iatrogenic, vascular, viral, or neoplastic damage to the trigeminal nerve. We present a rare case of TTS in a 32-year-old woman who was referred to us with progressive numbness in the right upper and lower lip region.


Assuntos
Hipestesia/diagnóstico , Doenças do Nervo Trigêmeo/diagnóstico , Adulto , Diagnóstico Diferencial , Progressão da Doença , Feminino , Humanos , Hipestesia/tratamento farmacológico , Perda de Seguimento , Imageamento por Ressonância Magnética , Prednisona/uso terapêutico , Síndrome , Doenças do Nervo Trigêmeo/tratamento farmacológico
5.
J Assoc Physicians India ; 61(6): 417-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24640212

RESUMO

Hematuria is a cardinal manifestation of renal disease and forms a cornerstone of nephrologic diagnosis. A systemic approach is required to delineate the source of hematuria to the kidney or urinary tract. We present the case of 14 years old boy who presented to us with history of passing red colour urine since 3 month not associated with pain who was subsequently diagnosed to have of Thin Basement Membrane Disease.


Assuntos
Hematúria/diagnóstico , Adolescente , Humanos , Masculino
6.
Aesthet Surg J Open Forum ; 5: ojad073, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37638341

RESUMO

Background: Gynecomastia surgery is one of the most common aesthetic procedures in males. There is a lack of objective analytical parameters to judge outcomes. In this study, the authors aim to introduce novel anthropometric measurements and analysis techniques for the objective assessment of surgical outcomes based on specific aesthetic targets. Objectives: To introduce quantification of gynecomastia surgery outcomes and compare the results among the different grades of gynecomastia. Methods: A total of 192 patients with gynecomastia were included. The patient cases were grouped according to grades and a set of anthropometric measurements were taken both before the operation and 6 months postoperatively. Liposuction and glandular excision were done through minimal incisions in all grades of gynecomastia, with the addition of ultrasound and nipple areola complex (NAC) lifting plaster in selected Grade 3 and all Grade 4 cases. Results: A statistically significant improvement in the perimeter of the triangular relationship of sternal notch and nipples, the elevation of the NAC, the reduction of the area of the NAC, and the correction of asymmetry of the chest were seen in all grades of gynecomastia, with increased differences in higher grades. Conclusions: A systematic objective analysis of the specific aesthetic targets helps to reliably compare results in a standard way and for carrying out improvisation of surgeons' techniques. Meanwhile, this approach helps identifying the need for customization, eventually providing symmetric and aesthetically pleasing surgical results.

7.
J Enzyme Inhib Med Chem ; 27(6): 849-53, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21988189

RESUMO

A series of 3-[3-(substituted phenyl)-1-phenyl-1H-pyrazol-5-yl]-2H-chromen-2-one (4a-k) were synthesized by reaction of 3-[2,3-dibromo-3-(substituted phenyl)propanoyl]-2H-chromen-2-one (3 a-k) with phenyl hydrazine in presence of triethylamine in absolute ethanol, characterized by spectral data and screened for their in vitro antibacterial activity against gram-positive and gram-negative bacteria. Among the series, compounds 4d, 4h and 4i displayed an encouraging antibacterial activity profile as compared to reference standard drug ciprofloxacin against tested bacterial strains.


Assuntos
Antibacterianos/síntese química , Bacillus subtilis/efeitos dos fármacos , Benzopiranos/síntese química , Escherichia coli/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Pirazóis/síntese química , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Bacillus subtilis/crescimento & desenvolvimento , Benzopiranos/farmacologia , Ciprofloxacina/farmacologia , Escherichia coli/crescimento & desenvolvimento , Etanol/química , Etilaminas/química , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Fenil-Hidrazinas/química , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pirazóis/farmacologia , Staphylococcus aureus/crescimento & desenvolvimento , Relação Estrutura-Atividade
8.
Colloids Surf B Biointerfaces ; 215: 112478, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35390596

RESUMO

Glycolipid, ganglio-N-tetraosylceramide (asialo-GM1), on the mammalian cells are known to be recognized by type IV pili of Pseudomonas aeruginosa. In this work, we show that asialo-GM1 can also be recognized by Lectin A (LecA), another adhesin protein of the P. aeruginosa, by a fluorescent polarization assay, a label-free bacterial motility enabled binding assay, and bacterial mutant studies. On hydrated semi-solid gel surfaces, asialo-GM1 enables swarming and twitching motilities, while on solid surfaces facilitates the bacterial adherence of P. aeruginosa. These results indicate that asialo-GM1 can modulate bioactivities, adherence, and motilities, that are controlled by opposite signaling pathways. We demonstrate that when a solution of pilin monomers or LecA proteins are spread on hydrated gel surfaces, the asialo-GM1 mediated swarming motility is inhibited. Treatment of artificial liposomes containing asialo-GM1 as a component of lipid bilayer with pilin monomers or LecA proteins caused transient leakage of encapsulated dye from liposomes. These results suggest that pili and LecA proteins not only bind to asialo-GM1 but can also cause asialo-GM1 mediated leakage. We also show that both pili and LecA mutants of P. aeruginosa adhere to asialo-GM1 coated solid surfaces, and that a class of synthetic ligands for pili and LecA inhibits both pili and LecA-mediated adherence of P. aeruginosa on asialo-GM1-coated surfaces.


Assuntos
Gangliosídeo G(M1) , Pseudomonas aeruginosa , Animais , Aderência Bacteriana/fisiologia , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/metabolismo , Fímbrias Bacterianas/metabolismo , Gangliosídeo G(M1)/metabolismo , Lectinas/metabolismo , Lectinas/farmacologia , Ligantes , Lipossomos/metabolismo , Mamíferos/metabolismo , Pseudomonas aeruginosa/metabolismo
9.
ACS Infect Dis ; 8(8): 1582-1593, 2022 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-35658414

RESUMO

Bacteria readily form resilient phenotypes to counter environmental and antibiotic stresses. Here, we demonstrate a class of small molecules that inhibit a wide range of Pseudomonas aeruginosa phenotypes and enable antibiotics to kill previously tolerant bacteria, preventing the transition of tolerant bacteria into a persistent population. We identified two proteins, type IV pili and lectin LecA, as receptors for our molecules by methods including a new label-free assay based on bacterial motility sensing the chemicals in the environment, the chemical inhibition of bacteriophage adsorption on pili appendages of bacteria, and fluorescence polarization. Structure-activity relationship studies reveal a molecule that inhibits only pili appendage and a class of chimeric ligands that inhibit both LecA and pili. Important structural elements of the ligand are identified for each protein. This selective ligand binding identifies the phenotypes each protein receptor controls. Inhibiting LecA results in reducing biofilm formation, eliminating small colony variants, and is correlated with killing previously tolerant bacteria. Inhibiting pili appendages impedes swarming and twitching motilities and pyocyanin and elastase production. Because these phenotypes are controlled by a broad range of signaling pathways, this approach simultaneously controls the multiple signaling mechanisms preventing bacteria to elude antibiotic treatments.


Assuntos
Pseudomonas aeruginosa , Fatores de Virulência , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Bactérias/metabolismo , Lectinas/metabolismo , Ligantes , Fenótipo , Pseudomonas aeruginosa/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
10.
BMJ Case Rep ; 14(1)2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33462041

RESUMO

Masseter hypertrophy (MH) is an uncommon disorder which can cause both aesthetic and functional problems. The most common aetiological factors associated with MH are habit of chewing gum, clenching and/or bruxism. The treatment of MH includes conservative management as well as surgical resection of the enlarged muscle and/or bone. Injection of botulinum toxin type A is a relatively new and minimally invasive method for management of masseter muscle hypertrophy, which offers many advantages over conventional surgical management. This paper reports a case of unilateral MH of unknown origin which was treated with injection of botulinum toxin type A, resulting in satisfactory reduction in the volume of muscle and improvement of facial aesthetics.


Assuntos
Toxinas Botulínicas Tipo A/uso terapêutico , Hipertrofia/diagnóstico , Músculo Masseter/anormalidades , Fármacos Neuromusculares/uso terapêutico , Feminino , Humanos , Músculo Masseter/efeitos dos fármacos , Adulto Jovem
11.
Natl J Maxillofac Surg ; 12(2): 255-261, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34483586

RESUMO

INTRODUCTION: Dexmedetomidine is a selective alpha-2 adrenoceptor agonist. It is conventionally used as a sedative in the intensive care unit. However, recently, the application of dexmedetomidine as an adjuvant to a local anesthetic agent has been studied. The present study intends to evaluate the effectiveness of dexmedetomidine as an adjuvant to 2% plain lignocaine for surgical removal of impacted mandibular third molar and to compare the efficacy of dexmedetomidine with 2% plain lignocaine with 2% lignocaine and 1:200000 adrenaline. MATERIALS AND METHODS: A total of 80 patients who required surgical removal of impacted mandibular third molar extraction were included in the study. Patients were randomly divided into two groups using a computer-generated table. Patients in the study group received 2% plain lignocaine with 1 mcg/ml dexmedetomidine. Patients in the control group received 2% lignocaine with 1:200000 adrenaline. The parameters evaluated were onset and duration of action, pulse rate, blood pressure, oxygen saturation, and blood loss. RESULTS: Onset of action was faster and the duration of action was longer when dexmedetomidine was used with lignocaine as a local anesthetic agent. The vital parameters in both the groups were stable. Bleeding at the surgical site was less in the dexmedetomidine group. CONCLUSION: The study concluded that the combination of dexmedetomidine with lignocaine enhances the local anesthetic potency of lignocaine when injected for nerve blocks.

12.
ChemMedChem ; 16(12): 1975-1985, 2021 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-33666373

RESUMO

Bacteria in general can develop a wide range of phenotypes under different conditions and external stresses. The phenotypes that reside in biofilms, overproduce exopolymers, and show increased motility often exhibit drug tolerance and drug persistence. In this work, we describe a class of small molecules that delay and inhibit the overproduction of alginate by a non-swarming mucoid Pseudomonas aeruginosa. Among these molecules, selected benzophenone-derived alkyl disaccharides cause the mucoid bacteria to swarm on hydrated soft agar gel and revert the mucoid to a nonmucoid phenotype. The sessile (biofilm) and motile (swarming) phenotypes are controlled by opposing signaling pathways with high and low intracellular levels of bis-(3',5')-cyclic diguanosine monophosphate (cdG), respectively. As our molecules control several of these phenotypes, we explored a protein receptor, pilin of the pili appendages, that is consistent with controlling these bioactivities and signaling pathways. To test this binding hypothesis, we developed a bacterial motility-enabled binding assay that uses the interfacial properties of hydrated gels and bacterial motility to conduct label-free ligand-receptor binding studies. The structure-activity correlation and receptor identification reveal a plausible mechanism for reverting mucoid to nonmucoid phenotypes by binding pili appendages with ligands capable of sequestering and neutralizing reactive oxygen species.


Assuntos
Alginatos/metabolismo , GMP Cíclico/análogos & derivados , Proteínas de Fímbrias/antagonistas & inibidores , Pseudomonas aeruginosa/efeitos dos fármacos , Sítios de Ligação/efeitos dos fármacos , GMP Cíclico/química , GMP Cíclico/farmacologia , Proteínas de Fímbrias/metabolismo , Ligantes , Oxirredução , Fenótipo , Pseudomonas aeruginosa/metabolismo , Relação Estrutura-Atividade
13.
ACS Omega ; 5(49): 32023-32031, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33344856

RESUMO

The application of lipid-based drug delivery technologies for bioavailability enhancement of drugs has led to many successful products in the market for clinical use. Recent studies on amine-containing heterolipid-based synthetic vectors for delivery of siRNA have witnessed the United States Food and Drug Administration (USFDA) approval of the first siRNA drug in the year 2018. The studies on various synthetic lipids investigated for delivery of such nucleic acid therapeutics have revealed that the surface pK a of the constructed nanoparticles plays an important role. The nanoparticles showing pK a values within the range of 6-7 have performed very well. The development of high-performing lipid vectors with structural diversity and falling within the desired surface pK a is by no means trivial and requires tedious trial and error efforts; therefore, a practical solution is called for. Herein, an attempt to is made provide a solution by predicting the statistically significant pK a through a predictive quantitative structure-activity relationship (QSAR) model. The QSAR model has been constructed using a series of 56 amine-containing heterolipids having measured pK a values as a data set and employing a partial least-squares regression coupled with stepwise (SW-PLSR) forward algorithm technique. The model was tested using statistical parameters such as r 2, q 2, and pred_r 2, and the model equation explains 97.2% (r 2 = 0.972) of the total variance in the training set and it has an internal (q 2) and an external (pred_r 2) predictive ability of ∼83 and ∼63%, respectively. The model was validated by synthesizing a series of designed heterolipids and comparing measured surface pK a values of their nanoparticle assembly using a 2-(p-toluidino)-6-napthalenesulfonic acid (TNS) assay. Predicted and measured surface pK a values of the synthesized heterolipids were in good agreement with a correlation coefficient of 93.3%, demonstrating the effectiveness of this QSAR model. Therefore, we foresee that our developed model would be useful as a tool to cut short tedious trial and error processes in designing new amine-containing heterolipid vectors for delivery of nucleic acid therapeutics, especially siRNA.

14.
J Family Med Prim Care ; 9(3): 1340-1347, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32509613

RESUMO

BACKGROUND AND AIM: C-reactive protein (CRP) is a type I acute phase protein, which can increase up to 1000 fold after the onset of a stimulus. It is a phylogenetically highly conserved plasma protein with homolog in vertebrates and many invertebrates that participate in systemic response to inflammation. Serum C-reactive protein levels are raised in patients with myocardial infarction and periodontitis, providing a potential mechanism to link destructive periodontal disease with an increased risk for other atherosclerotic complications. The purpose of the present study was to estimate and compare the levels of hs- C Reactive protein in chronic periodontitis patients before and after non-surgical periodontal therapy. METHODS: The study sample consisted of 45 individuals of age group 30-60 years that was divided into two groups Group I (control) and Group II (patients with chronic generalized periodontitis). The clinical parameters such as plaque index, calculus index, gingival index, probing pocket depth, clinical attachment level, and serum hs-CRP levels were recorded for these individuals. RESULTS: The patients with healthy gingiva possessed a mean hs-CRP level of 0.252 ± 0.0393 which was lower as compared to the patients with chronic periodontitis. In periodontitis patients mean levels of hs-CRP was 0.106 ± 0.029 which reduced to 0.044 ± 0.027 after periodontal therapy. A significantly elevated CRP level was found in subjects with periodontitis compared to the controls. CONCLUSION: The serum levels of C-reactive protein were elevated in patients with periodontitis and this might be a diagnostic marker for cardiovascular diseases.

15.
J Family Med Prim Care ; 9(4): 1834-1840, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32670927

RESUMO

Lymphomas constitute the third most common neoplasm in head and neck region arising from the lymphoreticular system. Malignant lymphomas are divided into Hodgkin's disease and non-Hodgkin's lymphoma (NHL). NHL comprises approximately 5% of head and neck malignancies and displays a wide range of appearances comparable with Hodgkin's disease. Hodgkin's and non-Hodgkin's lymphomas are seen in the head and neck region, but extranodal disease, with or without lymph node involvement, is more common among NHL patients. Extranodal involvement includes the areas such as Waldeyer's ring (i.e., the tonsils, pharynx, and base of the tongue), salivary glands, orbit, paranasal sinuses, and thyroid glands. There are several classification systems for categorizing NHL out of which WHO classification for lymphoid neoplasms is mostly followed. This review describes the pathogenesis of NHL and explains some of the important NHL (Marginal zone B-cell Lymphoma, follicular lymphoma, mantle cell lymphoma).

16.
Ann Afr Med ; 18(3): 121-126, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31417011

RESUMO

Inflammation is often associated with the development and progression of cancer. The cells responsible for cancer-associated inflammation are genetically stable and thus are not subjected to rapid emergence of drug resistance; therefore, the targeting of inflammation represents an attractive strategy both for cancer prevention and for cancer therapy. Tumor-extrinsic inflammation is caused by many factors, including bacterial and viral infections, autoimmune diseases, obesity, tobacco smoking, asbestos exposure, and excessive alcohol consumption, all of which increase cancer risk and stimulate malignant progression. In contrast, cancer-intrinsic or cancer-elicited inflammation can be triggered by cancer-initiating mutations and can contribute to malignant progression through the recruitment and activation of inflammatory cells. Both extrinsic and intrinsic inflammations can result in immunosuppression, thereby providing a preferred background for tumor development. The current review provides a link between inflammation and cancer development.


Résumé L'inflammation est souvent associée au développement et à la progression du cancer. Les cellules responsables de l'inflammation associée au cancer sont génétiquement stables et ne subissent donc pas l'émergence rapide d'une pharmacorésistance; par conséquent, le ciblage de l'inflammation représente une stratégie attrayante à la fois pour la prévention du cancer et pour le traitement du cancer. L'inflammation tumorale extrinsèque est causée par de nombreux facteurs, notamment: infections bactériennes et virales, maladies auto-immunes, obésité, tabagisme, exposition à l'amiante et consommation excessive d'alcool, le tout qui augmentent le risque de cancer et stimulent la progression maligne. En revanche, l'inflammation intrinsèque au cancer ou provoquée par le cancer peut être déclenchée par des mutations initiant un cancer et peuvent contribuer à la progression maligne par le recrutement et l'activation de cellules inflammatoires. Tous les deux les inflammations extrinsèques et intrinsèques peuvent entraîner une immunosuppression, fournissant ainsi un fond préféré pour le développement de la tumeur. le l'examen actuel établit un lien entre l'inflammation et le développement du cancer.


Assuntos
Transformação Celular Neoplásica/imunologia , Inflamação/imunologia , Neoplasias/imunologia , Microambiente Tumoral/imunologia , Humanos , Inflamação/complicações , Macrófagos/imunologia , Neoplasias/etiologia , Neoplasias/patologia
17.
Top Curr Chem (Cham) ; 374(5): 61, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27573503

RESUMO

Sonochemical reactors are based on the generation of cavitational events using ultrasound and offer immense potential for the intensification of physical and chemical processing applications. The present work presents a critical analysis of the underlying mechanisms for intensification, available reactor configurations and overview of the different applications exploited successfully, though mostly at laboratory scales. Guidelines have also been presented for optimum selection of the important operating parameters (frequency and intensity of irradiation, temperature and liquid physicochemical properties) as well as the geometric parameters (type of reactor configuration and the number/position of the transducers) so as to maximize the process intensification benefits. The key areas for future work so as to transform the successful technique at laboratory/pilot scale into commercial technology have also been discussed. Overall, it has been established that there is immense potential for sonochemical reactors for process intensification leading to greener processing and economic benefits. Combined efforts from a wide range of disciplines such as material science, physics, chemistry and chemical engineers are required to harness the benefits at commercial scale operation.


Assuntos
Sonicação/métodos , Biotecnologia , Cristalização , Composição de Medicamentos , Hidrodinâmica , Micro-Ondas , Pressão , Temperatura , Raios Ultravioleta , Eliminação de Resíduos Líquidos
18.
Ultrason Sonochem ; 30: 79-86, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26639635

RESUMO

The present work investigates the application of hydrodynamic cavitation (HC) for the pretreatment of wheat straw with an objective of enhancing the biogas production. The hydrodynamic cavitation reactor is based on a stator and rotor assembly. The effect of three different speeds of rotor (2300, 2500, 2700 rpm), wheat straw to water ratios (0.5%, 1% and 1.5% wt/wt) and also treatment times as 2, 4 and 6 min have been investigated in the work using the design of experiments (DOE) approach. It was observed that the methane yield of 31.8 ml was obtained with untreated wheat straw whereas 77.9 ml was obtained with HC pre-treated wheat straw confirming the favourable changes during the pre-treatment. The combined pre-treatment using KOH and HC gave maximum yield of biogas as 172.3 ml. Overall, it has been established that significant enhancement in the biogas production can be obtained due to the pretreatment using HC which can also be further intensified by combination with chemical treatment.


Assuntos
Biocombustíveis/análise , Reatores Biológicos , Hidrodinâmica , Sonicação , Triticum/química , Biomassa , Caules de Planta/química , Esgotos/microbiologia
19.
J Appl Physiol (1985) ; 99(3): 877-83, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15860681

RESUMO

Sensitivity of glucose transport to stimulation by insulin has been shown to occur concomitant with activation of the AMP-activated protein kinase (AMPK) in skeletal muscle, suggesting a role of AMPK in regulation of insulin action. The purpose of the present study was to evaluate a possible role of AMPK in potentiation of insulin action in muscle cells. The experimental model involved insulin-responsive C2C12 myotubes that exhibit a twofold increase in glucose transport in the presence of insulin. Treatment of myotubes with the AMPK activator 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR), followed by a 2-h recovery, augmented the ability of insulin to stimulate glucose transport. Similarly, incubation in hyperosmotic medium, another AMPK-activating treatment, acted synergistically with insulin to stimulate glucose transport. Furthermore, the increase in insulin action caused by hyperosmotic stress was prevented by inclusion of compound C, an AMPK inhibitor, in hyperosmotic medium. In addition, iodotubercidin, a general kinase inhibitor that is effective against AMPK, also prevented the combined effects of insulin and hyperosmotic stress on glucose transport. The new information provided by these data is that previously reported AICAR effects on insulin action are generalizable to myotubes, hyperosmotic stress and insulin synergistically increase glucose transport, and AMPK appears to mediate potentiation of insulin action.


Assuntos
Aminoimidazol Carboxamida/análogos & derivados , Insulina/farmacologia , Complexos Multienzimáticos/metabolismo , Mioblastos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Ribonucleotídeos/farmacologia , Proteínas Quinases Ativadas por AMP , Aminoimidazol Carboxamida/farmacologia , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Transporte Biológico Ativo/fisiologia , Linhagem Celular , Relação Dose-Resposta a Droga , Glucose/metabolismo , Camundongos , Complexos Multienzimáticos/efeitos dos fármacos , Mioblastos/efeitos dos fármacos , Pressão Osmótica/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/efeitos dos fármacos
20.
Exp Biol Med (Maywood) ; 230(11): 845-52, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16339749

RESUMO

Levodopa reportedly inhibits insulin action in skeletal muscle. Here we show that C2C12 myotubes produce levodopa and that insulin-stimulated glucose transport is enhanced when endogenous levodopa is depleted. Exogenous levodopa prevented the stimulation of glucose transport by insulin (P < 0.05) and increased cAMP concentrations (P < 0.05). The decrease in insulin-stimulated glucose transport caused by levodopa was attenuated by propranolol (a beta-adrenergic antagonist) and prevented by NSD-1015 (NSD), an inhibitor of DOPA decarboxylase (DDC; converts levodopa to dopamine). Propranolol and NSD both prevented levodopa-related increases in [cAMP]. However, the effects of levodopa were unlikely to be dependent on the conversion of levodopa to catecholamines because we could detect neither DDC in myotubes nor catecholamines in media after incubation of myotubes with levodopa. The data suggest the possibility of novel autocrine beta-adrenergic action in C2C12 myotubes in which levodopa, produced by myotubes, could have hormone-like effects that impinge on glucose metabolism.


Assuntos
Comunicação Autócrina/fisiologia , Dopaminérgicos/metabolismo , Levodopa/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Músculo Esquelético/metabolismo , Mioblastos Esqueléticos/metabolismo , Antagonistas Adrenérgicos beta/farmacologia , Animais , Inibidores das Descarboxilases de Aminoácidos Aromáticos , Comunicação Autócrina/efeitos dos fármacos , Transporte Biológico Ativo/efeitos dos fármacos , Transporte Biológico Ativo/fisiologia , Linhagem Celular , AMP Cíclico/metabolismo , Dopa Descarboxilase/metabolismo , Dopamina/metabolismo , Dopaminérgicos/farmacologia , Glucose/metabolismo , Hidrazinas/farmacologia , Hipoglicemiantes/metabolismo , Hipoglicemiantes/farmacologia , Insulina/metabolismo , Insulina/farmacologia , Levodopa/farmacologia , Camundongos , Propranolol/farmacologia
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