Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
1.
J Environ Manage ; 268: 110584, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32383665

RESUMO

It is proposed a closed-loop treatment cycle for Cr(III) removal from contaminated soils (2080 mg/kg). The treatment includes the use of lactic acid as washing agent, and the recovery of both Cr(II) and lactic acid from the spent solution. Results indicate that Cr(III) removal efficiency can be very high, passing 70% in all tested operative conditions. The metal forms strong complexes with lactic acid, and therefore cannot be eliminated through direct precipitation simply increasing the pH value. Therefore, lactic acid is preliminarily extracted from the solution using n-butanol at very acidic pH. The obtained extraction degree is generally high, varying between 0.5 and 1 according to the amount of used n-butanol solution. After lactic acid extraction, almost 100% of chromium can be recovered through precipitation in alkaline conditions. Lactic acid, in turns, can be purified and reused for a new washing treatment, separating it from n-butanol solution through water extraction. The extraction efficiency is once more satisfying (around 0.5), and not dependent on the operative pH.


Assuntos
Poluentes do Solo , Cromo , Poluição Ambiental , Ácido Láctico , Solo
2.
J Pediatr Urol ; 15(2): 166.e1-166.e7, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30528650

RESUMO

INTRODUCTION: The nocturnal polyuria is considered a significant predictive value for response to desmopressin. The cutoff value useful to define nocturnal polyuria is still a matter of debate. Moreover, it is current notion that maximal voided volume (MVV) could be used as a predictor for desmopressin response. OBJECTIVE: The objective of this study was to assess the impact of different definitions of nocturnal polyuria (and of its frequency) and MVV in predicting the response to desmopressin. STUDY DESIGN: A total of 103 patients with frequent monosymptomatic nocturnal enuresis (≥4 wet nights/week) were enrolled. A bladder diary over a 4-day period was collected. The MVV was defined as the highest micturition volume detected at bladder diary. Nocturnal diuresis was measured in 5 wet nights. Then, patients were administered with 120 mcg of sublingual desmopressin. After 2 months, if there was no complete response, the dose was increased to 240 mcg. Nocturnal polyuria was defined as follows: 1.Definition 1: nocturnal urine production >130% of the expected bladder capacity (EBC). 2. Definition 2: >100% EBC. 3. Definition 3: > 20×(age + 9) mL. The primary outcome was 'response to desmopressin' after 3 months of treatment. RESULTS: Fifty-three patients responded to desmopressin. Comparing the responses to desmopressin on the basis of the three definitions of nocturnal polyuria, no significant difference was found. There was no cutoff value of nocturnal polyuria expressed as %EBC useful in providing a significant receiver-operating characteristic (ROC) curve. The area under the ROC curve for MVV expressed as %EBC was 0.67 (95% confidence interval [CI], 0.54-0.80; p = 0.01). A MVV >103.1% of EBC had 78.8% (95% CI, 61.1-91.0) sensitivity and 47.5% (95% CI, 31.5-63.9) specificity for predicting response to desmopressin. Among the patients with nocturnal polyuria according to definition 1, a higher percentage of subjects with nocturnal polyuria in 4 out of 5 or 5 out of 5 nights responded to desmopressin, compared with other patients. Patients presenting with nocturnal polyuria according to definition 3 in 5 out of 5 nights showed a 100% of response to desmopressin. At multivariate analysis, the only significant odds ratio (OR) to respond to desmopressin was that of patients with nocturnal polyuria according to definition 1 in >3 nights (OR = 7.1, 95% CI, 1.3-40.3). DISCUSSION AND CONCLUSIONS: The presence or absence of nocturnal polyuria-according to all three definitions-in at least one night was not effective in predicting the response to desmopressin. Predictors of desmopressin response were nocturnal polyuria in >3 out of 5 wet nights according to definition 1 and in 5 out of 5 wet nights according to definition 3.


Assuntos
Antidiuréticos/uso terapêutico , Desamino Arginina Vasopressina/uso terapêutico , Enurese Noturna/tratamento farmacológico , Poliúria/tratamento farmacológico , Criança , Feminino , Humanos , Masculino , Estudos Prospectivos , Recidiva , Resultado do Tratamento
3.
Water Res ; 106: 450-460, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27764695

RESUMO

Imidazole-based compounds are used as reagents for the manufacturing of other compounds including imidazolium-based ionic liquids, which have been recently proposed as a green alternative to conventional solvents. Since some imidazole-based compounds have been demonstrated to be harmful to aquatic organisms, the removal of imidazole, 1-methylimidazole, 1-ethyl-3-methyl-imidazolium chloride and 1-butyl-3-methyl-imidazolium chloride from aqueous solutions was attempted by biological oxidation, direct UV254 photolysis, and UV254/H2O2 process at pH 5.5 and 8.5. Results showed that UV254/H2O2 treatment is an effective tool for the removal of the selected compounds at both pHs. In fact, the kinetic constants of the reaction between the photogenerated HO radicals and the four target compounds, estimated by means of both numerical and competition kinetic method, range between 2.32·109 M-1 s-1 and 5.52 ·109 M-1 s-1. Moreover, an ecotoxicity assessment of the contaminated water before and after initial treatment without further processing was assessed by using two living aquatic organisms: Raphidocelis subcapitata and Daphnia magna. The results of this assessment not only corresponded closely to previous findings (in terms of EC50 values) reported in the literature, but also indicated that, in some cases, UV254/H2O2 oxidation by-products could be even more toxic than parent compounds.


Assuntos
Peróxido de Hidrogênio , Água , Animais , Biodegradação Ambiental , Daphnia , Imidazóis/química , Líquidos Iônicos/química
4.
J Hazard Mater ; 318: 515-525, 2016 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-27450344

RESUMO

Benzoylecgonine (BE), the main cocaine metabolite, has been detected in numerous surface water and treatment plants effluents in Europe and there is urgent need for effective treatment methods. In this study, the removal of BE by the UV254/H2O2 process from different water matrices was investigated. By means of competition kinetics method, the kinetic constant of reaction between BE and the photogenerated hydroxyl radicals (OH) was estimated resulting in kOH/BE=5.13×10(9)M(-1)s(-1). By-products and water matrices scavengers effects were estimated by numerical modeling of the reaction kinetics for the UV254/H2O2 process and validated in an innovative microcapillary film (MCF) array photoreactor and in a conventional batch photoreactor. The ecotoxicity of the water before and after treatment was evaluated with four organisms Raphidocelis subcapitata, Daphnia magna, Caenorhabditis elegans, and Vicia faba. The results provided evidence that BE and its transformation by-products do not have significant adverse effects on R. subcapitata, while D. magna underwent an increase of lipid droplets. C. elegans was the most sensitive to BE and its by-products. Furthermore, a genotoxicity assay, using V. faba, showed cytogenic damages during the cell mitosis of primary roots.


Assuntos
Cocaína/análogos & derivados , Peróxido de Hidrogênio/química , Mutagênicos/toxicidade , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/toxicidade , Água/química , Animais , Organismos Aquáticos , Cocaína/isolamento & purificação , Cocaína/toxicidade , Ecotoxicologia , Cinética , Plantas , Raios Ultravioleta
5.
Photochem Photobiol Sci ; 14(10): 1844-52, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26205482

RESUMO

The reconstitution of the integral membrane protein photosynthetic reaction center (RC) in polymersomes, i.e. artificial closed vesicles, was achieved by the micelle-to-vesicle transition technique, a very mild protocol based on size exclusion chromatography often used to drive the incorporation of proteins contemporarily to liposome formation. An optimized protocol was used to successfully reconstitute the protein in a fully active state in polymersomes formed by the tri-block copolymers PMOXA22-PDMS61-PMOXA22. The RC is very sensitive to its solubilizing environment and was used to probe the positioning of the protein in the vesicles. According to charge-recombination experiments and to the enzymatic activity assay, the RC is found to accommodate in the PMOXA22 region of the polymersome, facing the water bulk solution, rather than in the PDMS61 transmembrane-like region. Furthermore, polymersomes were found to preserve protein integrity efficiently as the biomimetic lipid bilayers but show a much longer temporal stability than lipid based vesicles.


Assuntos
Membranas Artificiais , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Polímeros/química , Interações Hidrofóbicas e Hidrofílicas , Cinética , Transporte Proteico , Rhodobacter sphaeroides/enzimologia
6.
Oncogene ; 34(20): 2597-608, 2015 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-25023698

RESUMO

REV-ERBα and REV-ERBß nuclear receptors regulate several physiological processes, including circadian rhythm and metabolism. A previous study reported the REV-ERBα gene to be co-overexpressed with ERBB2 in breast cancer cell lines. Surprisingly, we found that several tumor types, including a number of breast cancer cell lines, predominantly express the REV-ERBß variant. This pattern was independent of ERBB2 and ER status, and opposite to that of non-cancer mammary epithelial HMEC cells, in which REV-ERBα was the major variant. Consistent with this molecular profile, REV-ERB target genes in both circadian and metabolic pathways were derepressed upon silencing of REV-ERBß, but not REV-ERBα. Strikingly, we found that REV-ERBß is a determinant of sensitivity to chloroquine, a clinically relevant lysosomotropic agent that suppresses autophagy. The cytoprotective function of REV-ERBß appears to operate downstream of autophagy blockade. Through compound screening, we identified ARN5187, a novel lysosomotropic REV-ERBß ligand with a dual inhibitory activity toward REV-ERB-mediated transcriptional regulation and autophagy. Remarkably, although ARN5187 and chloroquine share similar lysosomotropic potency and have a similar effect on autophagy inhibition, ARN5187 is significantly more cytotoxic. Collectively, our results reveal that dual inhibition of REV-ERBß and autophagy is an effective strategy for eliciting cytotoxicity in cancer cells. Furthermore, our discovery of a novel inhibitor compound of both REV-ERB and autophagy may provide a scaffold for the discovery of new multifunctional anticancer agents.


Assuntos
Antineoplásicos/farmacologia , Autofagia/efeitos dos fármacos , Citotoxinas/farmacologia , Neoplasias/tratamento farmacológico , Receptores Citoplasmáticos e Nucleares/antagonistas & inibidores , Proteínas Repressoras/antagonistas & inibidores , Autofagia/genética , Ensaios de Seleção de Medicamentos Antitumorais , Células HEK293 , Células Hep G2 , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Membro 1 do Grupo D da Subfamília 1 de Receptores Nucleares/genética , Membro 1 do Grupo D da Subfamília 1 de Receptores Nucleares/metabolismo , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo
7.
Mitochondrion ; 17: 34-41, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24846800

RESUMO

The nucleotide change A to G at position m.3243 in the mitochondrial tRNA leucine (UUR) gene (MT-TL1) is the most common point mutation reported in association with the Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like episodes (MELAS) syndrome. Since the original description of this disorder, factors including random mitochondrial segregation and consequent variable tissue heteroplasmy are recognised to contribute to a much broader phenotypic spectrum associated with the MT-TL1 m.3243A>G mutation, often rendering the process of making a diagnosis complex. Reliance on clinicians' referral patterns means that for most molecular diagnostic laboratories, their positive identification rates for the common pathogenic mitochondrial DNA (mtDNA) mutations, including MT-TL1 m.3243A>G, is often relatively low compared to those reported in clinically targeted research studies. Herein, we report our results of consecutive prospective screening of 745 patients with a clinically suspected mitochondrial syndrome encompassing features associated with MT-TL1 m.3243A>G mutation.


Assuntos
DNA Mitocondrial/genética , Genes Mitocondriais , Síndrome MELAS/epidemiologia , Síndrome MELAS/genética , Mutação Puntual , RNA de Transferência de Leucina/genética , Adolescente , Adulto , Idoso , Criança , Feminino , Testes Genéticos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Adulto Jovem
8.
Mitochondrion ; 13(4): 269-76, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23524250

RESUMO

Multiple Symmetrical Lipomatosis (MSL) is an unusual disorder characterized by the development of axial lipomas in adulthood. The pathoetiology of lipoma tissue in MSL remains unresolved. Seven patients with MSL were followed for a mean period of 12 years (8-20 years). All patients had cervical lipomas ranging from subtle lesions to disfiguring masses; six patients had peripheral neuropathy and five had proximal myopathy. Myoclonus, cerebellar ataxia and additional lipomas were variably present. All patients showed clinical progression. Muscle histopathology was consistent with mitochondrial disease. Five patients were positive for mtDNA point mutation m.8344A>G, three of whom underwent lipoma resection--all samples were positive for uncoupling protein-1 mRNA (unique to brown fat). Lipoma from one case stained positive for adipocyte fatty-acid protein-2 (unique to brown fat and immature adipocytes). This long-term study hallmarks the phenotypic heterogeneity of MSL's associated clinical features. The clinical, genetic and molecular findings substantiate the hypothesis that lipomas in MSL are due to a mitochondrial disorder of brown fat.


Assuntos
Tecido Adiposo Marrom/patologia , Lipomatose Simétrica Múltipla/etiologia , Lipomatose Simétrica Múltipla/patologia , Doenças Mitocondriais/patologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Neuromuscul Disord ; 22(5): 401-5, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22357363

RESUMO

This 54year old woman presented with symptoms of sensory ataxic neuropathy, with cerebellar features. She developed further weakness, visual disturbances with diplopia, dysarthria and dysphasia. After her death at 66years, she was found to have compound heterozygous mutations of POLG1 gene in muscle, and Southern blot showed low levels of multiple deletions of mitochondrial DNA. Neuropathological examination showed profound dorsal column and dorsal spinocerebellar tract degeneration, degeneration of dorsal root ganglia and Clarke's nucleus in spinal cord and severe predominantly sensory peripheral neuropathy. The brain showed severe neuronal loss and gliosis in substantia nigra, medial posterior thalamus and head of caudate. Excess numbers of COX-negative fibres and "ragged-red" fibres were found in five skeletal muscles sampled.


Assuntos
DNA Polimerase Dirigida por DNA/genética , Predisposição Genética para Doença/genética , Doenças Musculares/genética , Mutação , Doenças do Sistema Nervoso Periférico/genética , Doenças da Medula Espinal/genética , Degenerações Espinocerebelares/genética , Idoso , DNA Polimerase gama , DNA Mitocondrial/genética , Evolução Fatal , Feminino , Genes Recessivos/genética , Heterozigoto , Humanos , Pessoa de Meia-Idade , Doenças Musculares/diagnóstico , Doenças do Sistema Nervoso Periférico/diagnóstico , Doenças do Sistema Nervoso Periférico/patologia , Doenças da Medula Espinal/diagnóstico , Doenças da Medula Espinal/patologia , Degenerações Espinocerebelares/patologia
10.
Eur J Med Genet ; 55(1): 67-70, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21971480

RESUMO

We report a new case of 8q interstitial duplication in a patient with dysmorphic features, umbilical hernia, cryptorchidism, short stature, congenital heart defect and mild mental retardation (MR). Chromosome analysis with high resolution QFQ bands showed 46,XY, 8q+, which was interpreted as a partial duplication of the distal long arm of chromosome 8 (q22 â†’ qter). This chromosomal aberration was further characterized using fluorescence in situ hybridization (FISH) analyses with multiple DNA probes and array-CGH (Comparative Genomic Hybridization) experiment which demonstrated a de novo direct duplication (8)(q22.2-q24.3). We have compared this case with other partially trisomic 8q patients reported in literature and highlighted the common clinical features in 8q22-8q24 duplication syndrome.


Assuntos
Anormalidades Múltiplas/genética , Duplicação Cromossômica , Fenótipo , Trissomia/genética , Cariótipo Anormal , Anormalidades Múltiplas/patologia , Criança , Pré-Escolar , Coloração Cromossômica , Cromossomos Humanos Par 8/genética , Sondas de DNA , Humanos , Lactente , Masculino
11.
Water Res ; 43(10): 2710-6, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19380156

RESUMO

The contemporary removal of organic pollutants from aqueous solution and electricity generation is studied in the present work by means of an experimental device resulting from the combination of a photocatalytic reactor and an electrochemical cell. The proposed system relies on the capability of Cu2+ ions to reduce in the presence of TiO2, (solar) UV radiations and a sacrificial organic agent. In the anodic solution of the combined photoreactor-cell, Cu0 is oxidized to Cu2+ and the latter is reduced again to the lowest oxidation state. The use of different sacrificial agents ranging from formic acid (FA) to glycerol (GLY) to glucose (GLU) is investigated along with the adoption of two different cathodes for the cell, the first based again on the couple Cu2+/Cu0 and the second on the couple O2/H2O.


Assuntos
Fontes de Energia Bioelétrica , Fotoquímica/métodos , Eliminação de Resíduos Líquidos/métodos , Cobre/química , Formiatos/química , Glucose/química , Glicerol/química , Oxirredução , Titânio/química , Raios Ultravioleta
12.
Water Sci Technol ; 52(8): 257-64, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16312975

RESUMO

The kinetics of aerobic biodegradation were studied for 20 aromatic species by using sludges taken from a municipal sewage treatment plant. The reproducibility of the results is tested with respect to the period of collection of the sludges and the wastewater treatment plant where they were taken. The comparison of kinetic constants estimated for investigated chemicals allows evaluation of the effect on the reactivity due to the presence of single groups (i.e. -OH, -CH3, -Cl, -NO2) into the aromatic structures. The search for easy structure-reactivity relations is also attempted by using some group contributing methods.


Assuntos
Bactérias Aeróbias/metabolismo , Hidrocarbonetos Aromáticos/metabolismo , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Cinética
13.
Water Sci Technol ; 50(5): 23-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15497825

RESUMO

The possibility of applying main AOP techniques, namely ozonation, H2O2/UV photolysis and TiO2 photocatalysis to provide a significant reduction of toxicity of pharmaceutical mixtures has been evaluated. For the preparation of the mixture six pharmaceuticals were chosen among those found at highest concentrations in Sewage Treatment Plant effluents, namely carbamazepine, clofibric acid, diclofenac, sulfamethoxazole, ofloxacin and propranolol. The blue-green alga Synechococcus leopoliensis and the rotifer Brachyonus calyciflorus were utilised to assess the toxicity of the mixtures after AOP treatments. All the toxicity tests were performed using chronic standardized bioassays. The best results were obtained with ozonation. With this type of treatment a complete removal of mixture toxicity on S. leopolensis was obtained even after the shortest time of application (1 min). The ozonation treatment leads also to removal of all the pharmaceutical mixture toxicity on B. calyciflorus, by applying the oxidizing agent for at least for 2 minutes.


Assuntos
Oxidantes Fotoquímicos/química , Preparações Farmacêuticas/química , Esgotos/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Animais , Bioensaio , Cianobactérias/metabolismo , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Monitoramento Ambiental , Estudos de Avaliação como Assunto , Ozônio/química , Preparações Farmacêuticas/isolamento & purificação , Rotíferos/metabolismo
14.
J Hazard Mater ; 113(1-3): 1-10, 2004 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-15363509

RESUMO

The present work aims at assessing both thermodynamic and kinetic parameters of the esterification process of the (S)-carnitine, using calorimetric techniques. The use of the system acetic anhydride/nitric acid/acetic acid as esterifying agent and the explosive behaviour of nitric esters lead to safety considerations that have been investigated by hypothesizing some common process deviations. In particular, it has been investigated in adiabatic conditions both the batch addition of acetic anhydride and the effect of an initial temperature higher than those required by the process.


Assuntos
Ácido Acético/química , Anidridos Acéticos/química , Carnitina/análogos & derivados , Carnitina/química , Nitratos/síntese química , Gestão da Segurança/métodos , Calorimetria/métodos , Esterificação , Explosões/prevenção & controle , Cinética , Modelos Químicos , Ácido Nítrico/química
15.
Intern Med J ; 34(1-2): 10-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-14748908

RESUMO

BACKGROUND: Many diverse pathogenic mitochondrial DNA (mtDNA) mutations have been described since 1988. The Melbourne Neuromuscular Research Institute (MNRI) has undertaken diagnostic detection of selected mtDNA mutations since 1990. MtDNA mutations screened have included point mutations associated with Leber's hereditary optic neuropathy (LHON; G3460A, G11778A and T14484C), mitochondrial encephalopathy lactic acidosis and stroke-like episodes (MELAS; A3243G), myoclonus epilepsy and ragged red fibres (MERRF; A8344G) and Leigh's syndrome/neuropathy ataxia retinitis pigmentosa (LS/NARP; T8993C/G). Samples have also been screened for deletions/ rearrangements associated with Kearns-Sayre syndrome (KSS) and chronic progressive external ophthalmoplegia (CPEO). AIMS: To present an audit of the MNRI mtDNA diagnostic service between 1990 and 2001, encompassing 1725 referred patients. METHODS: The detection techniques carried out included polymerase chain reaction amplification of mtDNA combined with restriction fragment length polymorphism analysis for mtDNA point mutation detection, supplemented with selected sequence analysis and Southern blots for the detection of deletions/ rearrangements. Tissues tested included blood, hair and skeletal muscle. RESULTS: Of the 1184 patients screened for MELAS A3243G, 6.17% were positive for the mutation, whereas for MERRF A8344G, 2.21% carried the mutation and for LS/NARP T8993C/G, 0.32% carried the mutation. The outcomes for the LHON mutations were G11778A, 6.60%, T14484C, 5.76% and G3460A, 0.29%. Of the patients referred for KSS and CPEO, 17.72% had deletions/rearrangements. CONCLUSIONS: Overall, the detection rate of mtDNA point mutations was low. The protean clinical features of mitochondrial disorders and the frequency of partial phenotypes lead to requests for tests in many patients with a relatively low likelihood of mtDNA mutations. An improved algorithm could involve mutation screening appropriate to the phenotype using sequencing of selected mtDNA regions in patients with a high likelihood of mtDNA disease. Features increasing the likelihood of mtDNA mutations include the following: (i) a typical phenotype, (ii) a maternal inheritance pattern and (iii) histochemical evidence of mitochondrial abnormality in the muscle biopsy. Efficient laboratory diagnosis of mtDNA disease involves good communication between the physician and laboratory scientists, coupled with screening of the appropriate tissue.


Assuntos
DNA Mitocondrial/genética , Doenças Mitocondriais/diagnóstico , Mutação Puntual , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Adulto , Austrália , Southern Blotting , Humanos , Mutação , Análise de Sequência de DNA
17.
Neuromuscul Disord ; 12 Suppl 1: S61-6, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12206798

RESUMO

Targeted correction of mutations in muscle can be delivered by direct i.m. injection of corrective DNA to the dystrophic muscle or by autologous injection of cells that have been genetically corrected after isolation from the individual with the dystrophic muscle. The successful application of chimeraplasty and short fragment homologous replacement to correct the exon 23 nonsense mdx transition at the mouse dys locus has opened up the possibility that with further development, targeted gene correction may have some future application for the treatment of muscular dystrophies. In vitro, application of targeted gene correction at the mdx dys locus results in better correction efficiencies than when applied directly to dystrophic muscle. This suggests that at least for the time being, a strategy involving ex vivo correction may be advantageous over a direct approach for delivery of gene correction to dystrophic muscle. This, particularly in view of recent developments indicating that bone-marrow-derived cells are able to systemically remodel dystrophic muscle, whilst penetration of DNA introduced to muscle is limited to individually injected muscles. Application of targeted gene correction to Duchenne dystrophy needs to account for the fact that about 65% of Duchenne muscular dystrophy cases involve large frame-shift deletion of gene sequence at the dys locus. Traditionally, whilst targeted gene correction is able to restore point mutations entirely, it remains to be seen as to whether a strategy for the 'correction' of frame shift deletions may be engineered successfully. This communication discusses the possibility of applying targeted gene correction to dystrophic muscle in Duchenne dystrophy.


Assuntos
Células da Medula Óssea , Distrofina/genética , Terapia Genética/métodos , Antígenos Comuns de Leucócito/metabolismo , Distrofias Musculares/terapia , Animais , Células da Medula Óssea/imunologia , Transplante de Medula Óssea , Transplante de Células , Mutação da Fase de Leitura , Marcação de Genes , Técnicas de Transferência de Genes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos mdx , Distrofias Musculares/genética , Distrofias Musculares/imunologia , Distrofia Muscular Animal/terapia , Distrofia Muscular de Duchenne/terapia
18.
Tissue Cell ; 34(5): 305-14, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12270257

RESUMO

Sperm morphology and spermatogenesis were examined in the oligochaete annelid Isochaetides arenarius, a species belonging to the subfamily Tubificinae inhabiting the sediments of Lake Baikal. As all tubificines, Isochaetides produces two types of spermatozoa, named eusperm and parasperm. The eusperm are the fertilizing male gametes and consist, in sequence, of an acrosome, a nucleus, a mitochondrial mid-piece, and a tail. The parasperm have the same general architecture, but differ in cytological details: the acrosome is shorter, devoid of a perforatorium, and the acrosome vesicle has a different, simpler, shape. The nucleus is much shorter and rectilinear (the eusperm nucleus is twisted). The mid-piece mitochondria are less numerous but their overall volume is larger. The flagellum has a plasma membrane largely separated from the axoneme, and is devoid of glycogen granules. After mating, the two sperm types gather in the spermathecae to form spermatozeugmata; in these structures the parasperm form an external sheath involving the centrally located eusperm and their tails are connected by conspicuous septate junctions. Parasperm nuclei are produced through a process of fragmentation of the 'spermatocytes', whereas the flagellar basal bodies are produced by a process similar to that giving rise to basal bodies in ciliated epithelia.


Assuntos
Linhagem da Célula/fisiologia , Oligoquetos/crescimento & desenvolvimento , Oligoquetos/ultraestrutura , Espermatogênese/fisiologia , Espermatozoides/ultraestrutura , Testículo/crescimento & desenvolvimento , Testículo/ultraestrutura , Acrossomo/fisiologia , Acrossomo/ultraestrutura , Animais , Núcleo Celular/fisiologia , Núcleo Celular/ultraestrutura , Fertilização/fisiologia , Flagelos/fisiologia , Flagelos/ultraestrutura , Masculino , Microscopia Eletrônica , Mitocôndrias/fisiologia , Mitocôndrias/ultraestrutura , Oligoquetos/fisiologia , Espermatozoides/classificação , Espermatozoides/fisiologia , Testículo/fisiologia
20.
Water Res ; 35(1): 109-20, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11257864

RESUMO

The ozonation of pyruvic acid (2-ketopropionic acid) in aqueous solutions, catalyzed by Mn(II) and Mn(IV) ions, has been studied at three different pH values (pH = 1.1, 2.0 and 3.0). A mathematical model of the unsteady operation of the experimental reactor has been developed, which takes into account the reactions occurring in the liquid phase and the ozone mass transfer from the gas bubbles. Those reactions have been described with two alternative kinetic models, both made out of four elementary steps. The two kinetic models correlate the experimental data with a fair accuracy, respectively at the lowest and at the highest pH examined. In particular, at pH = 3.0, the ozonation results are inhibited by the acetate ions produced by the reaction itself. This effect has been correctly described in the terms of a complex formed with the low oxidation-state manganese, which successively reacts with the dissolved ozone.


Assuntos
Manganês , Ozônio/química , Ácido Pirúvico/química , Concentração de Íons de Hidrogênio , Cinética , Modelos Químicos , Ácido Pirúvico/isolamento & purificação , Soluções , Purificação da Água/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA