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1.
Eur Arch Paediatr Dent ; 24(1): 33-42, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36114997

ABSTRACT

PURPOSE: To evaluate the survival rate of primary maxillary anterior teeth following intrusive luxation and identify associated factors. METHODS: A retrospective longitudinal study was conducted at a primary dental trauma centre using 88 dental records of children with intrusive luxation between 2007 and 2018. The variables of interest were time the tooth remained in the alveolus, degree of intrusion, accentuated overjet, lip protection, visible plaque, compromised germ of the permanent successor, clinical signs of infectious and inflammatory processes, endodontic treatment, pulp canal obliteration, sex, age at the time of trauma, family income, mother's schooling, and immediate care. Descriptive, bivariate, and Cox regression analyses were performed (p < 0.05; 95% CI). RESULTS: The 88 dental records of children with intrusive luxation included 128 teeth. Survival rate throughout the follow-up period was 65.6% (n = 84). Age older than three years and eight months (HR 2.28; 95% CI 1.04-4.99; p = 0.039), the development of an infectious process (HR 3.51; 95% CI 1.39-8.86; p = 0.008), development of an inflammatory process (HR 2.35; 95% CI 1.17-4.71; p = 0.016) and compromised germ of the permanent successor (HR 4.38; 95% CI 1.99-9.61; p < 0.001) were associated with a lower survival rate of intruded primary maxillary anterior teeth. CONCLUSION: The survival rate during the follow-up period of intruded primary maxillary anterior teeth was considered high. A significantly lower survival rate was associated with age, the occurrence of an infectious process and inflammatory process, and the compromised germ of the permanent successor.


Subject(s)
Root Resorption , Tooth Avulsion , Child , Humans , Child, Preschool , Longitudinal Studies , Retrospective Studies , Incisor/injuries , Root Resorption/complications , Dental Pulp Necrosis , Tooth Avulsion/therapy , Tooth Avulsion/epidemiology
2.
Sci Rep ; 10(1): 231, 2020 01 14.
Article in English | MEDLINE | ID: mdl-31937827

ABSTRACT

Polycystic kidney disease is a complex clinical entity which comprises a group of genetic diseases that leads to renal cyst development. We evaluated the most suitable housekeeping genes for microRNA expression by RT-qPCR analyses of kidney tissues in Pkd1-deficient mouse models from a panel of five candidates genes (miR-20a, miR-25, miR-26a, miR-191 and U6) and 3 target genes (miR-17, miR-21 and let-7a) using samples from kidneys of cystic mice (Pkd1flox/flox:Nestincre, CY), non-cystic controls (Pkd1flox/flox, NC), Pkd1-haploinsufficient (Pkd1+/-, HT), wild-type controls (Pkd1+/+, WT), severely cystic mice (Pkd1V/V, SC), wild-type controls (CO). The stability of the candidate genes was investigated using NormFinder, GeNorm, BestKeeper, DataAssist, and RefFinder software packages and the comparative ΔCt method. The analyses identified miR-26a as the most stable housekeeping gene for all kidney samples, miR-20a for CY and NC, miR-20a and miR-26a for HT and WT, and miR-25 and miR-26a for SC and CO. Expression of miR-21 was upregulated in SC compared to CO and trends of miR-21 upregulation and let-7a downregulation in CY and HT compared to its control kidneys, when normalized by different combinations of miR-20a, miR-25 and miR-26a. Our findings established miR-20a, miR-25, and miR-26a as the best housekeeping genes for miRNA expression analyses by RT-qPCR in kidney tissues of Pkd1-deficient mouse models.


Subject(s)
Gene Expression Profiling , Genes, Essential/genetics , Kidney/metabolism , MicroRNAs/genetics , Protein Kinase C/deficiency , Animals , Haploinsufficiency , Mice , Protein Kinase C/genetics
3.
Med Vet Entomol ; 32(1): 41-47, 2018 03.
Article in English | MEDLINE | ID: mdl-28833280

ABSTRACT

The cattle tick, Rhipicephalus microplus (Canestrini, 1888) (Ixodida: Ixodidae), is the most important ectoparasite in cattle-breeding areas and is responsible for severe economic losses. Synthetic acaricides have been used to control this parasite. However, the need for safer products has stimulated the search for new acaricides, such as those to be obtained from medicinal plants. The essential oil of Syzygium aromaticum (clove) has many biological properties and shows great potential for use in veterinary applications. In the context of the need for new agents, this study investigated the in vitro properties of the hydrolate, essential oil and the main constituent of S. aromaticum, eugenol, in formulated and free applications against larvae and females of R. microplus. Eugenol and the essential oil caused 100% mortality in larvae at starting applications of 2.5 mg/mL and 5.0 mg/mL, respectively. The hydrolate showed no activity. Both eugenol and essential oil had good efficacy in adult immersion tests at 50 mg/mL and achieved 100% efficacy at a concentration of 100 mg/mL. The results of these tests reaffirm the important potential of clove essential oil and eugenol.


Subject(s)
Acaricides , Clove Oil , Eugenol , Rhipicephalus , Syzygium/chemistry , Tick Control , Animals , Female , Larva/growth & development , Rhipicephalus/growth & development
4.
Opt Express ; 24(4): 3385-92, 2016 Feb 22.
Article in English | MEDLINE | ID: mdl-26906997

ABSTRACT

In this paper, we numerically investigate the impact of polarisation mode dispersion on the efficiency of compensation of nonlinear transmission penalties for systems employing one of more inline phase conjugation devices. We will show that reducing the spacing between phase conjugations allows for significantly improved performance in the presence polarisation mode dispersion or a significant relaxation in the acceptable level of polarization mode dispersion. We show that these results are consistent with previously presented full statistical analysis of nonlinear transmission appropriately adjusted for the reduced section length undergoing compensation.

5.
Transl Psychiatry ; 6: e707, 2016 Jan 05.
Article in English | MEDLINE | ID: mdl-26731444

ABSTRACT

Cognitive functioning can be differentially modulated by components of the immune system. Interferon-γ (IFNγ) is a pro-inflammatory cytokine whose production is altered in many conditions displaying some degree of cognitive deficits, although its role in cognitive functioning is still unclear. Here we show that the absence of IFNγ selectively enhances cognitive behaviours in tasks in which the hippocampus is implicated. Moreover, the absence of IFNγ leads to volumetric and cell density changes that are restricted to the dorsal part of the hippocampus. In the dorsal hippocampus, the absence of this pro-inflammatory cytokine leads to an increase in the numbers of newly born neurons in the subgranular zone of the dentate gyrus (DG), an adult neurogenic niche known to support learning and memory, and to an enlargement of the dendritic arborization of DG granule and cornu ammonis (CA)1 pyramidal neurons. Moreover, it also modestly impacts synaptic plasticity, by decreasing the paired-pulse facilitation in the Schaffer collateral to CA1 pyramidal cell synapses. Taken together, our results provide evidence that IFNγ is a negative regulator of hippocampal functioning, as its absence positively impacts on dorsal hippocampus structure, cell density, neuronal morphology and synaptic plasticity. Importantly, these neuroplastic changes are associated with improved performance in learning and memory tasks. Therefore, blockage of the IFNγ signalling may present as promising therapeutic targets for the treatment of inflammation-associated cognitive dysfunction.


Subject(s)
Cognition/physiology , Hippocampus/physiology , Interferon-gamma , Neuronal Plasticity/physiology , Animals , Female , Male , Mice , Mice, Inbred C57BL
6.
Eur Rev Med Pharmacol Sci ; 19(4): 694-700, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25753888

ABSTRACT

OBJECTIVE: Vancomycin (VCM) is a tricyclic glycopeptide antibiotic produced by Streptococcus orientalis. Widely used in hospitals, it is indicated to fight severe infections caused by Gram-positive bacteria, especially with the advent of MRSA (methicillin-resistant Staphylococcus aureus), penicillin-resistant pneumococci among others. Furthermore, it is indicated for the treatment of patients allergic to penicillins and cephalosporins. Dose recommendations, dilution rates and types of infusion are controversial and also result in toxic effects. Aim of this paper was to perform a literature review showing the therapeutic and adverse effects of vancomycin. MATERIALS AND METHODS: This is a literature review of recent articles published on MEDLINE and SciELO databases in English, Portuguese and Spanish. RESULTS: The main adverse effects of vancomycin are: hypotension, phlebitis, nephrotoxicity, ototoxicity, hypersensitivity reactions, red man syndrome, neutropenia, chills, fever, interstitial nephritis. CONCLUSIONS: The use of vancomycin is still very common; however, inadequate doses and prolonged therapy pose a risk of increasing minimum inhibitory concentrations (MICs), resulting in subtherapeutic levels, treatment failures and toxicity. Therefore, further studies should be conducted to optimize the administration of vancomycin, monitoring treatments from the beginning in order to ensure a safe and effective use of the drug.


Subject(s)
Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/therapeutic use , Gram-Positive Bacterial Infections/drug therapy , Vancomycin/adverse effects , Vancomycin/therapeutic use , Cephalosporins/therapeutic use , Gram-Positive Bacteria/drug effects , Humans , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Neutropenia/chemically induced
7.
Water Sci Technol ; 69(4): 862-7, 2014.
Article in English | MEDLINE | ID: mdl-24569288

ABSTRACT

Wastewater drainage systems asset management decisions, in particular regarding rehabilitation interventions, are largely dependent on close-circuit television (CCTV) inspection results. However, the results of CCTV inspections are affected by several sources of uncertainty. Within the present communication, the inspector's uncertainty is quantified by comparing periodic inspection reports from three trunk sewers of a Portuguese sewer system. The inspections were carried out by the same experienced inspector using the same equipment. Therefore, the uncertainties from the lack of experience and the difference of the inspector and equipment were ruled out. The protocol uncertainty is also quantified comparing the results obtained with the Water Research Center (WRc) and the National Research Council of Canada (NRC) protocols condition ratings. Both operational and structural condition rating were analysed, but emphasis was given to the later since it dictates the repair and replacement interventions.


Subject(s)
Drainage, Sanitary/standards , Facility Design and Construction , Sewage , Water Movements , Environmental Monitoring , Waste Disposal, Fluid
8.
Eur J Paediatr Dent ; 12(2): 107-11, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21668282

ABSTRACT

AIM: The purpose of the present study was to assess the prevalence of malocclusion in the primary dentition in a randomised representative sample of Brazilian preschool children. MATERIALS AND METHODS: A cross-sectional survey was carried out in Belo Horizonte, Brazil, involving 1069 male and female preschool children from 60 to 71 months of age, randomly selected from public and private preschools and daycare centers. A questionnaire addressing demographic data was sent to parents/guardians in order to characterise the sample. The oral examination of the children was performed by a single, previously calibrated dentist (kappa inter-examiner agreement value = 0.82). The criterion for the categorisation of malocclusion was at least one of the following conditions: posterior crossbite, overjet (> 2 mm), anterior crossbite, anterior open bite and deep overbite. Univariate analysis was performed using the SPSS software RESULTS: The prevalence of malocclusion was 46.2%. Deep overbite was the most prevalent alteration (19.7% of the sample). Posterior crossbite was diagnosed in 13.1% of the children; 10.5% had accentuated overjet; 7.9% had anterior open bite; and 6.7% had anterior crossbite. CONCLUSION: Malocclusion in primary dentition is becoming a significant problem. The prevalence in the present study was high, especially vertical and transversal malocclusions.


Subject(s)
Malocclusion/epidemiology , Tooth, Deciduous/pathology , Brazil/epidemiology , Child , Child, Preschool , Cross-Sectional Studies , Educational Status , Female , Humans , Income , Male , Malocclusion/classification , Open Bite/epidemiology , Parents/education , Pilot Projects , Population Surveillance , Prevalence , Social Class
9.
Eur J Paediatr Dent ; 11(2): 59-65, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20635838

ABSTRACT

AIM: The aim of the present study was to assess the prevalence of traumatic dental injury (TDI) in primary teeth and determine predisposing factors. MATERIALS AND METHODS: A cross-sectional study was carried out on 388 male and female Brazilian preschool children between 60 and 71 months of age. A questionnaire addressing demographic data and history of TDI was sent to parents/caregivers. Socioeconomic status was determined using the Social Vulnerability Index (SVI), family income, number of people in the household and parents/caregivers' schooling. The chi-square test was used for the statistical analysis. RESULTS: The prevalence of TDI was 62.1%; 61.7% of the teeth were affected by enamel fracture. Statistically significant associations were found between TDI and increased overjet [OR = 2.24, 95% CI = 1.11- 4.55] and anterior crossbite [OR = 0.38, 95% CI=0.17-0.87]. No statistically significant associations were found between TDI and number of people in the household, family income, social vulnerability, parents/caregivers' schooling, lip competence, overbite, anterior open bite and dental caries (p>0.05). CONCLUSION: The prevalence of TDI was high and enamel fracture was the most common sign of TDI. Children with an increased overjet suffer more TDIs. Socioeconomic factors had no influence over the prevalence of TDI.


Subject(s)
Malocclusion/complications , Tooth Injuries/epidemiology , Brazil/epidemiology , Chi-Square Distribution , Child, Preschool , Cross-Sectional Studies , Dental Enamel/injuries , Female , Humans , Male , Prevalence , Risk Factors , Social Class , Surveys and Questionnaires , Tooth Injuries/etiology , Tooth, Deciduous
10.
Eur J Paediatr Dent ; 10(3): 135-40, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19761288

ABSTRACT

AIM: The aim of the study was to perform a preliminary validation of the Brazilian version of the Child Perceptions Questionnaire 8-10 (CPQ 8-10). METHODS: The sample used to test the measurement equivalence was made up of 59 children from 8 to 10 years of age at the Federal University of Minas Gerais, Brazil. The CPQ 8-10 was administered, and clinical exams were performed by a single examiner, calibrated for the diagnosis of dental caries (Kappa= 0.98) and malocclusion (weighted Kappa and intraclass correlation coefficient = 0.66-1.00). The children were divided into three groups according to their clinical condition (22 with cavitated carious lesions; 20 with malocclusion; 17 with both oral conditions). STATISTICS: The internal consistency of the instrument was assessed by Cronbach's alpha Coefficient. The Intraclass correlation coefficient (ICC) was used for the test-retest reliability (40 children). Discriminant validity was determined using the Kruskal-Wallis test. RESULTS: An assessment of the psychometric properties revealed the instrument to be reliable (Cronbach's alpha=0.92 for the total scale and 0.63-0.85 for the subscales), exhibiting excellent stability (ICC=0.96 for the total scale and 0.79-0.95 for the subscales). Construct validity was demonstrated through the significant correlations between the global indicators and subscales. There were statistically significant differences between the clinical groups regarding the total scale, thereby demonstrating discriminant validity (p=0.03). CONCLUSIONS: The preliminary validation of the Brazilian version of the CPQ 8-10 showed valid and reliable for use on Brazilian children.


Subject(s)
Oral Health , Psychometrics/methods , Quality of Life/psychology , Self-Assessment , Surveys and Questionnaires , Attitude to Health , Brazil , Child , Cross-Cultural Comparison , Dental Health Surveys , Female , Humans , Male , Reproducibility of Results , Statistics, Nonparametric
11.
Braz. j. phys. ther. (Impr.) ; 12(5): 379-385, set.-out. 2008. ilus, graf
Article in Portuguese | LILACS | ID: lil-499907

ABSTRACT

OBJETIVOS: Assim como a imagética motora, o reconhecimento de partes do corpo aciona representações somatosensoriais específicas. Essas representações são ativadas implicitamente para comparar o corpo com o estímulo. No presente estudo, investigou-se a influência da informação proprioceptiva da postura no reconhecimento de partes do corpo (mãos) e propõe-se a utilização dessa tarefa na reabilitação de pacientes neurológicos. MATERIAIS E MÉTODOS: Dez voluntários destros participaram do experimento. A tarefa era reconhecer a lateralidade de figuras da mão apresentada, em várias perspectivas e em vários ângulos de orientação. Para a figura da mão direita, o voluntário pressionava a tecla direita e para a figura da mão esquerda, a tecla esquerda. Os voluntários realizavam duas sessões: uma com as mãos na postura prona e outra com as mãos na postura supina. RESULTADOS: Os tempos de reação manual (TRM) eram maiores para as vistas e orientações, nas quais é difícil realizar o movimento real, mostrando que durante a tarefa, existe um acionamento de representações motoras para comparar o corpo com o estímulo. Além disso, existe uma influência da postura do sujeito em vistas e ângulos específicos. CONCLUSÕES: Estes resultados mostram que representações motoras são ativadas para comparar o corpo com o estímulo e que a postura da mão influencia esta ressonância entre estímulo e parte do corpo.


OBJECTIVE: Recognition of body parts activates specific somatosensory representations in a way that is similar to motor imagery. These representations are implicitly activated to compare the body with the stimulus. In the present study, we investigate the influence of proprioceptive information relating to body posture on the recognition of body parts (hands). It proposes that this task could be used for rehabilitation of neurological patients. METHODS: Ten right-handed volunteers participated in this experiment. The task was to recognize the handedness of drawings of a hand that were presented in different perspectives and several orientations. For drawings of a right hand, the volunteers pressed the right key, and for drawings of a left hand, they pressed the left key. The volunteers underwent two sessions: one with their hands in a prone posture and the other with their hands in a supine posture. RESULTS: The manual reaction time was longer for perspectives and orientations for which the real movement was difficult to achieve. This showed that, during the task, motor representations were activated to compare the body with the stimulus. Furthermore, the subject's posture had an influence in relation to specific perspectives and orientations. CONCLUSIONS: These results showed that motor representations are activated to compare the body with the stimulus, and that the position of the hand influences this resonance between the stimulus and the body part.

12.
Arch Toxicol ; 77(4): 194-200, 2003 Apr.
Article in English | MEDLINE | ID: mdl-12698234

ABSTRACT

Chronic cholestasis is characteristic of many human liver diseases. Renal injury has been often associated with this type of disease. The aim of this study was to evaluate the effect of cholestasis on kidney mitochondrial bioenergetics following in vivo chronic administration of alpha-naphthyl-isothiocyanate (ANIT), a known cholestatic agent. Serum markers of renal injury, kidney morphology and endogenous adenine nucleotides were measured in ANIT-treated rats (80 mg/kg per week s.c. for 16 weeks). Changes in membrane potential and mitochondrial respiration as well as alterations in mitochondrial calcium homeostasis were monitored. Cholestatic animals shown no alterations in renal morphology when compared with control. Additionally, following chronic ANIT administration, no significant alterations in mitochondrial respiratory function have been shown. The phosphorylation capacity of cholestatic kidney mitochondria was enhanced. Associated with these parameters, mitochondria from treated animals exhibited a decreased susceptibility to disruption of mitochondrial calcium homeostasis, due to permeability transition induction. These data suggest that, despite being submitted to chronic treatment with ANIT, kidney mitochondria from cholestasis-induced rats present some defense mechanisms to circumvent this aggression. They show improved phosphorylative capacity and, moreover, a decreased susceptibility to mitochondrial permeability transition induction, probably due to adaptative mechanisms of calcium transport.


Subject(s)
1-Naphthylisothiocyanate/toxicity , Cholestasis, Intrahepatic/chemically induced , Energy Metabolism/drug effects , Kidney/drug effects , Mitochondria/drug effects , 1-Naphthylisothiocyanate/administration & dosage , Adenine Nucleotides/metabolism , Animals , Calcium/metabolism , Cholestasis, Intrahepatic/metabolism , Cholestasis, Intrahepatic/pathology , Disease Models, Animal , Female , Injections, Intraperitoneal , Intracellular Membranes/drug effects , Intracellular Membranes/physiology , Kidney/metabolism , Kidney/pathology , Membrane Potentials/drug effects , Mitochondria/metabolism , Mitochondrial Swelling/drug effects , Phosphorylation , Rats , Rats, Wistar
13.
Water Sci Technol ; 45(3): 273-9, 2002.
Article in English | MEDLINE | ID: mdl-11905442

ABSTRACT

The aim of this document is to present and discuss the results of the experimental work undertaken in Laje stream, in a section near the village of Oeiras in Portugal. The work was developed with the main objective of characterising stormwater quality in Portuguese drainage systems, and to predict the effects of the performance of partially separate sewer systems on receiving waters. For this purpose, volume and characteristics of stormwater carried by a partially separated sewer system were estimated, both in terms of flow and Chemical Oxygen Demand (COD) loads. The study also analyses the eventual implementation of non-conventional solutions, as a way of reducing problems of bacteriological contamination of seawaters. This aspect is particularly important in Portugal, where the population is mainly concentrated in urban areas located down-stream of important drainage basins, close to the coastline. Therefore, sanitary sewer overflows discharging directly into receiving waters are frequent, with possible consequences in terms of bacteriological contamination of bathing areas. Based on experimental research and available data it was possible to collect informations regarding stormwater average COD and overflow coliform loads, and the occurrence of first flush effects.


Subject(s)
Sewage , Waste Disposal, Fluid , Water Pollution/prevention & control , Cities , Environmental Monitoring , Portugal , Rain , Water Movements , Water Supply
14.
Microbes Infect ; 3(12): 1015-9, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11580988

ABSTRACT

Intestinal microsporidiosis is recognised as an important cause of opportunistic infections in immunocompromised patients, especially those with AIDS. Two species are implicated in diarrhoea and other gastrointestinal disease in HIV-infected patients: Enterocytozoon bieneusi and Encephalitozoon intestinalis. Diagnosis of gastrointestinal microsporidiosis was made by detecting spores of the parasite in stool specimens with Weber's modified trichrome stain and with some optical brightening agents such as UVITEX 2B or calcofluor white M2R. The identification of microsporidiosis at the species level was made using appropriate primers with PCR. The diagnosis of intestinal microsporidiosis is currently performed in the parasitology laboratory. In a study of 215 HIV-infected patients, conducted from 1996 to 1999 (approximately n = 60/year), we found a prevalence of spores of microsporidia of 51.5% (n = 31) in 1996, 14.0% (n = 5) in 1997 and 12.5% (n = 8) in 1998 and 42.8% (n = 25) in 1999. Using PCR we found that E. intestinalis was the only species responsible for the gastrointestinal symptoms in 49 patients with microsporidian spores (71%) and E. bieneusi in 29% (n = 20).


Subject(s)
AIDS-Related Opportunistic Infections/complications , Intestinal Diseases, Parasitic/complications , Microsporidiosis/complications , Adult , Aged , Diarrhea/etiology , Female , Humans , Male , Middle Aged
15.
Toxicon ; 39(6): 757-61, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11137533

ABSTRACT

The presence of paralytic shellfish poisoning (PSP) toxins in cultures of Aphanizomenon flos-aquae, isolated from the Crestuma-Lever reservoir, was found by reversed phase high performance liquid chromatography employing two isocratic elution systems for the separation of PSP toxins. With the first isocratic elution protocol, the presence of apolar toxins as saxitoxin, decarbamoyl saxitoxin and neosaxitoxin not detected. On the other hand, GTX4, GTX1 and GTX3 as well as Cs toxins were present either in the Aphanizomenon flos-aquae cells collected directly from the bloom or in the other toxic isolates priorly cultivated in laboratory conditions.


Subject(s)
Bacterial Toxins/isolation & purification , Cyanobacteria/chemistry , Chromatography, High Pressure Liquid , Portugal , Shellfish
16.
Acta Crystallogr D Biol Crystallogr ; 56(Pt 5): 670-2, 2000 May.
Article in English | MEDLINE | ID: mdl-10771446

ABSTRACT

N-Acetylglucosamine 6-phosphate deacetylase (E.C. 3.5.1.25), an enzyme from Escherichia coli involved in aminosugar catabolism, has been crystallized by the vapour-diffusion technique using phosphate as precipitant. X-ray diffraction experiments show the crystals to belong to the orthorhombic crystal system, with space group P2(1)2(1)2. The unit-cell parameters are a = 82.09 (2), b = 114.50 (1), c = 80.17 (1) A. The crystals diffract to a maximum resolution of 1.8 A and an initial data set was collected to 2.0 A.


Subject(s)
Amidohydrolases/chemistry , Escherichia coli/enzymology , Amidohydrolases/isolation & purification , Crystallization , Crystallography, X-Ray/methods , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification
17.
Metabolism ; 48(9): 1115-9, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10484050

ABSTRACT

Respiratory indexes and the transmembrane electrical potential (delta psi) were evaluated in mitochondrial preparations from 6-month-old Goto-Kakizaki (GK) and Wistar rats in the presence of glutamate + malate and succinate. We found that in diabetic GK mitochondria, flavin adenine dinucleotide (FAD)-linked respiratory indexes (respiratory control ratio [RCR] and adenosine diphosphate [ADP] to oxygen ratio [ADP/O]) are increased and uncoupled respiration is largely enhanced, indicating increased respiratory chain activity in GK rats. Delta psi development in GK mitochondrial preparations, energized using glutamate + malate or succinate as substrates, and the repolarization rate upon phosphorylation of the added ADP were significantly higher in GK mitochondrial preparations. These results indicate an enhanced activity of the phosphorylation system, confirmed by evaluating delta psi development when the mitochondria are energized by adenosine triphosphate (ATP). Moreover, recovery of the potential upon a phosphorylative cycle is increased in GK mitochondria, reflecting a more efficient coupling between the phosphorylative and oxidative system. Contrasting with results obtained for alloxan- or streptozotocin-induced diabetic rats, this study clearly demonstrates no impairment of mitochondrial bioenergetics in diabetic GK rats. On the contrary, at this age, we observed a higher efficiency of the phosphorylation system as compared with Wistar rats.


Subject(s)
Diabetes Mellitus/genetics , Mitochondria, Liver/metabolism , Adenine Nucleotides/metabolism , Adenine Nucleotides/pharmacology , Animals , Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone/pharmacology , Cell Respiration , Diabetes Mellitus/metabolism , Energy Metabolism , Glutamic Acid/metabolism , Malates/metabolism , Male , Membrane Potentials , Onium Compounds/metabolism , Organophosphorus Compounds/metabolism , Oxygen Consumption , Phosphorylation , Rats , Succinic Acid/metabolism
18.
Life Sci ; 65(10): 1013-25, 1999.
Article in English | MEDLINE | ID: mdl-10499869

ABSTRACT

The respiratory function and the antioxidant capacity of liver mitochondrial preparations isolated from Goto-Kakizaki non-insulin dependent diabetic rats and from Wistar control rats, with the age of 6 months, were compared. It was found that Goto-Kakizaki mitochondrial preparations presented a higher coupling between oxidative and phosphorylative systems, compared to non-diabetic preparations. Goto-Kakizaki mitochondria presented a lower susceptibility to lipid peroxidation induced by ADP/Fe2+, as evaluated by the formation of thiobarbituric acid substances. The decreased susceptibility to peroxidation in diabetic rats was correlated with an increase in mitochondrial vitamin E (alpha-tocopherol) content and GSH/GSSG ratio. Moreover, the glutathione reductase activity was significantly increased, whereas the glutathione peroxidase was decreased. Superoxide dismutase activity was unchanged in diabetic rats. Fatty acid analyses showed that the content in polyunsaturated fatty acids of Goto-Kakizaki mitochondrial membranes was significantly higher compared to controls. These results indicate that the lower susceptibility to lipid peroxidation of mitochondria from diabetic rats was related to their antioxidant defense systems, and may correspond to an adaptative response of the cells against oxidative stress in the early phase of diabetes.


Subject(s)
Diabetes Mellitus, Type 2/metabolism , Glutathione/metabolism , Lipid Peroxidation , Mitochondria, Liver/metabolism , Oxidoreductases/metabolism , Vitamin E/metabolism , Animals , Antioxidants/metabolism , Blood Glucose/metabolism , Body Weight , Cell Respiration , Diabetes Mellitus, Type 2/genetics , Fatty Acids/metabolism , Glycated Hemoglobin/metabolism , Male , Mitochondria, Liver/chemistry , Oxygen Consumption , Rats , Rats, Mutant Strains , Rats, Wistar , Succinates/metabolism , Thiobarbituric Acid Reactive Substances/metabolism
19.
FEBS Lett ; 458(2): 103-6, 1999 Sep 17.
Article in English | MEDLINE | ID: mdl-10481045

ABSTRACT

Liver mitochondrial bioenergetics of Goto-Kakizaki (GK) rats (a model of non-insulin dependent diabetes mellitus) reveals a Delta Psi upon energization with succinate significantly increased relatively to control animals. The repolarization rate following ADP phosphorylation is also significantly increased in GK mitochondria in parallel with increased ATPase activity. The increase in the repolarization rate and ATPase activity is presumably related to an improved efficiency of F(0)F(1)-ATPase, either from a better phosphorylative energy coupling or as a consequence of an enlarged number of catalytic units. Titrations with oligomycin indicate that diabetic GK liver mitochondria require excess oligomycin pulses to completely abolish phosphorylation, relative to control mitochondria. Therefore, accepting that the number of operational ATP synthase units is inversely proportional to the amount of added oligomycin, it is concluded that liver mitochondria of diabetic GK rats are provided with extra catalytic units relative to control mitochondria of normal rats. Other tissues (kidney, brain and skeletal muscle) were evaluated for the same bioenergetic parameters, confirming that this feature is exclusive to liver from diabetic GK rats.


Subject(s)
Diabetes Mellitus, Type 2/metabolism , Mitochondria, Liver/metabolism , Adenosine Triphosphatases/metabolism , Animals , Brain/enzymology , Brain/physiology , Diabetes Mellitus, Type 2/enzymology , Diabetes Mellitus, Type 2/genetics , Energy Metabolism , Kidney/enzymology , Kidney/physiology , Male , Membrane Potentials/drug effects , Mitochondria, Liver/enzymology , Mitochondria, Liver/physiology , Mitochondria, Muscle/enzymology , Mitochondria, Muscle/physiology , Oligomycins/pharmacology , Phosphorylation , Rats , Rats, Inbred Strains , Rats, Wistar , Substrate Specificity , Titrimetry
20.
Acta Diabetol ; 36(4): 173-7, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10664324

ABSTRACT

Type 2 diabetes mellitus is one of the most common chronic metabolic diseases in man. Due to long-term complications of the disease, severely decreasing the quality of life of diabetic patients, early interventions to obviate the risk of complications are of major importance. Therefore, diabetic animal models are of major importance in research for interventional treatment of type 2 diabetes. In this work we investigated the possible alterations in mitochondrial energetic metabolism of Goto-Kakizaki (GK) rats during the progression of the disease, since glucose metabolism is closely related to intracellular ATP content. For that reason, respiratory indexes (state 4, state 3, RCR and ADP/O) were evaluated either in the presence of NAD- or FAD-linked substrates (glutamate + malate and succinate, respectively) in mitochondrial preparations of GK and control rats with 8, 12, 26 and 52 weeks of age. Until the age of 1 year (52 weeks) we found no impairment of mitochondrial respiratory indexes both in the presence of glutamate + malate and succinate. In conclusion, this study indicates that GK rat is a good model for studying the initial events of diabetes, since it presents no impairment of liver mitochondrial functions during the first year of life, contrasting clearly with pharmacological induced diabetes.


Subject(s)
Aging/metabolism , Diabetes Mellitus, Type 2/metabolism , Energy Metabolism , Liver/growth & development , Mitochondria, Liver/metabolism , Adenosine Diphosphate/metabolism , Adenosine Monophosphate/metabolism , Adenosine Triphosphate/metabolism , Analysis of Variance , Animals , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/physiopathology , Male , Oxygen Consumption , Rats , Rats, Mutant Strains , Rats, Wistar
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