Design of magnetorheological brake for forearm rotation of a wrist prosthesis.

A wrist joint in upper limb prostheses significantly increases its handling capacity. However, current prostheses cannot reproduce the ability of torque combined with the volume and weight of the human wrist. Consequently, they do not provide high efficiency in handling and generate user dissatisfaction. In this context, this study aims to optimal design a wrist supination and pronation brake to improve the handling capacity of an upper limb prosthesis. The wrist actuator consists of an EC motor and harmonic drive parallel with a magnetorheological brake. The brake guarantees a fast response time, low energy consumption, controllability, and small dimensions. A particle swarm algorithm is applied to optimize design variables to minimize mass and energy consumption. As a result, the brake provided resistive torque of 7.4 N.m with dimensions close to a healthy member and weighing 0.1972 kg. Finally, a finite element analysis confirmed a satisfactory magnetic flux for the magnetorheological brake operating conditions. The designed brake addressed all the desired characteristics and is suitable to integrate the forearm prosthesis with wrist rotation.

Family Cohesion Is Associated with the Self-Perceived Need for Dental Treatment among Adolescents.

This study explored the association between family cohesion and self-perceived need for dental treatment among adolescents. A school-based representative cross-sectional study was conducted with 746 students aged 15 to 19 randomly selected from schools in Campina Grande, Brazil. Parents/guardians provided information on sociodemographic data, and students completed questionnaires about the self-perceived need for dental treatment, dental pain, and family cohesion and adaptability (FACES III). Two dentists were trained (kappa >0.80) to diagnosis dental caries using the Nyvad criteria and assess adolescents' level of functional oral health literacy (BREALD-30). Descriptive analysis was performed, followed by nonadjusted and adjusted robust binary logistic regression for complex samples (α = 5%). The prevalence of self-perceived need for dental treatment was 88.6%. The presence of dental caries (OR = 2.10; IC 95%: 1.22-3.61), tooth loss (OR = 15.81; IC 95%: 2.14-116.56), dental pain in the last six months (OR = 1.87; IC 95%: 1.06-3.31), and enmeshed family cohesion type (OR = 10.23; IC 95%: 3.96-26.4) remained associated with the self-perceived need for dental treatment in the final model. In conclusion, dental caries, dental pain, tooth loss, and family cohesion influenced the self-perceived need for dental treatment in adolescents.

Effect of Robot-Assisted Therapy on Participation of People with Limited Upper Limb Functioning: A Systematic Review with GRADE Recommendations.

BACKGROUND: Previous studies have suggested that robot-assisted therapy (RT) is effective in treating impairment and that it may also improve individuals' participation. OBJECTIVE: To investigate the effect of RT on the participation of individuals with limited upper limb functioning (PROSPERO: CRD42019133880). Data Sources: PEDro, Embase, MEDLINE, CINAHL, Cochrane, AMED, and Compendex. Inclusion Criteria. We selected randomized or quasirandomized controlled studies comparing the effects of RT with minimal or other interventions on participation of individuals with limited upper limb functioning. Data Extraction and Synthesis. Methodological quality of the included studies was assessed using the 0-10 PEDro scale, and effect estimates were reported using standardized mean differences (SMDs) with 95% confidence intervals (CIs), and the certainty of the current evidence was assessed using the GRADE. RESULTS: Twelve randomized controlled studies involving 845 participants were included. The estimates of medium effects between RT and minimal intervention (MI) at a short-term follow-up were pooled, but there are no short-term effects between RT and OI. Standardized differences in means were as follows: 0.6 (95% CI 0.1 to 1.2) and 0.2 (95% CI -0.0 to 0.4). There were also no effects of additional RT in the short- or medium-term follow-up periods. Standardized differences in means were as follows: -0.6 (95% CI -1.1 to -0.1) and 0.2 (95% CI -0.3 to 0.8). The methodological quality of the included studies potentially compromised the effect estimates of RT. The existing evidence was very low-quality with many confounding variables between studies. CONCLUSIONS: For patients with upper limb neurological dysfunction, low-quality evidence supports RT over MI in terms of improving individual participation in the short term. The existing low- to very low-quality evidence does not support RT over OI in either the short- or medium-term follow-up periods with respect to community participation.

Parabens enhance the calcium-dependent testicular mitochondrial permeability transition: Their relevance on the reproductive capacity in male animals.

Parabens, alkyl ester derivatives from p-hydroxybenzoic acid, are extensively used as antimicrobial preservatives. Nonetheless, due to its widespread and massive employment, several studies highlighted the association between parabens and alterations in the reproductive system. This study aimed to relate the adverse effect of the most commonly used parabens in testis mitochondria with male fertility. From all the parabens used, propyl and butyl were the ones that most negatively decreased the respiratory control ratio. In the case of butyl, inhibitions of 20% and 60% were observed, respectively, at the lowest and highest concentration, when compared to the control group. The membrane potential was only significantly affected by propyl (14%) and butyl (31%), and at a concentration of 250 µM. Succinate dehydrogenase, cytochrome c oxidase, and ATPase activities showed a nonsignificant decrease. Cytochrome c reductase, on the other hand, showed statistically significant inhibitions for both propyl (56%) and butylparaben (55%). The susceptibility to the mitochondrial permeability transition pore (MPTP) opening was increased by all parabens, although this increase was markedly significant for propyl and butyl. These results show that the susceptibility of mitochondria to parabens is dependent on the alkyl chain length and parabens hydrophobicity, and the main mitochondrial target is Complex II-III and MPTP. Hence, this study demonstrates the contribution of parabens exposition to the inhibition of testis mitochondrial function and their putative noxious effect on the male reproductive system.

Rare dental developmental disturbance in primary and permanent teeth following trauma prior to tooth eruption: Case report.

Traumatic dental injuries are highly prevalent among preschool children. When occurring at a very young age (prior to the eruption of the primary teeth), such trauma can disturb the normal development of the permanent dentition and, more rarely, affect the primary dentition. This report describes a case of a patient who suffered dentoalveolar trauma at six months of age that caused rare developmental problems in the primary dentition, such as impaction, dilacerations, hypoplasia, and odontoma. Imaging revealed that alterations also occurred in the permanent dentition. This report demonstrates that dentoalveolar trauma prior to complete development of the dentition and even before the eruption of the primary teeth can lead to highly uncommon abnormalities in the primary dentition. Moreover, there may be repercussions in the permanent dentition when the germs of these teeth are injured by the intraosseous displacement of primary teeth.

The association of childhood sleep problems with the prevalence of traumatic dental injury in schoolchildren.

BACKGROUND/AIM: Sleep quality exerts an influence on attention level and motor skills and is associated with accidental injuries in children. The aim of this study was to evaluate the association between traumatic dental injury and sleep behaviour in children. MATERIAL AND METHODS: A cross-sectional study was conducted in a small city in southern Brazil with a representative sample of schoolchildren aged 8-10 years (n = 537). Weight and height were measured, and examinations were performed for the determination of clinical occlusion and traumatic dental injury. The parents answered the Sleep Behaviour Questionnaire and questions addressing socio-demographic characteristics. RESULTS: The prevalence of traumatic dental injury was 22% (95% CI: 19-26) and was higher among children who woke three to four times per night (PR = 3.30; 95% CI: 2.47-4.39), those who fell asleep in the parental bed (PR = 1.41; 95% CI: 1.09-1.83), those who were not in a good mood on waking up in the morning (PR = 1.30; 95% CI: 1.02-1.65), those who became sleepy while sitting and/or studying (PR = 1.57; 95% CI: 1.09-2.24) and while watching TV (PR = 1.41; 95% CI: 1.0005-1.97) and those who had bad dreams (PR = 1.35; 95% CI: 1.04-1.76). The Poisson multiple regression model with a multilevel approach revealed that the prevalence of traumatic dental injury was 1.51-fold higher among children with daytime drowsiness (PR = 1.51; 95% CI: 1.11-2.04) after adjusting for socio-demographic, occlusal and anthropometric variables. CONCLUSION: Sleep problems were associated with a higher prevalence of traumatic dental injury among the children analysed.

Contextual and individual determinants of oral health-related quality of life among five-year-old children: a multilevel analysis.

BACKGROUND: Contextual factors may influence oral health-related quality of life (OHRQoL) in children. The aim of the present study was to evaluate the influence of individual and contextual determinants of OHRQoL based on the perceptions of children. METHODS: A cross-sectional study was conducted with a representative sample of 769 five-year-old children from public and private preschools in a city in the countryside of northeast Brazil. Parents/caregivers answered questionnaires addressing psychological aspects, sociodemographic data and aspects of the child's oral health. The children answered the child version of the Scale of Oral Health Outcomes for five-year-old children and were submitted to oral examinations. Variables related to the context were obtained from the schools and official municipal publications. Unadjusted and adjusted multilevel Poisson regression models were used to investigate associations between variables. RESULTS: In the adjusted analysis, parent's/caregiver's schooling, household income, parent's/caregiver's age, a history of dental pain, dental caries and its consequences and traumatic dental injury were considered individual determinants of OHRQoL according to the children's self-reports. After the incorporation of the contextual determinants, the association between parent's/caregiver's schooling and OHRQoL lost its significance. Type of school was the context variable that remained associated with OHRQoL. DISCUSSION: Besides the clinical and sociodemographic individual characteristics, characteristics of the school environment in which the child studies are associated with self-reported impacts on OHRQoL.

The Waterbirth Project: São Bernardo Hospital experience.

INTRODUCTION: The following quantitative observational study aimed to analyse the maternal and neonatal outcomes of 90 low-risk pregnant women who gave birth in water at São Bernardo Hospital. METHODS: A form containing information on the obstetric history of the parturient, the type of immersion, and the labour and birth follow-up was used by midwives to collect the data. BACKGROUND: The Apgar score (at 1min after birth) used in this study, called Aqua Apgar, was adapted by Cornelia Enning. RESULTS: The mean water immersion time was 1h and 46min and had an influence on the duration of labour (mean 5h and 37min), with a statistically significant difference (P=0.004). There was a decreased cervical dilatation time and a shorter duration of the expulsion phase. In the immersion scenario, 30% of the women did not undergo any examination to assess the length of the cervix, and 57.8% presented intact perennial areas or first-degree tears. As for neonatal outcomes, during maternal immersion, 97% maintained normal fetal heart rates (between 110 and 160 beats per minute) and Aqua Apgar was higher than 7, both in the first minute (mean of 9.4) and in the fifth minute of life (mean of 9.9). CONCLUSION: These safety outcomes, based on sound scientific evidence, should increasingly support and inform clinical decisions and increase the number of waterbirths in health facilities. The results of this study align with growing evidence that suggests waterbirth is a safe delivery option and therefore should be offered to women.

Validity and Reliability of the Brazilian Version of the Rapid Estimate of Adult Literacy in Dentistry--BREALD-30.

OBJECTIVE: The aim of the present study was to translate, perform the cross-cultural adaptation of the Rapid Estimate of Adult Literacy in Dentistry to Brazilian-Portuguese language and test the reliability and validity of this version. METHODS: After translation and cross-cultural adaptation, interviews were conducted with 258 parents/caregivers of children in treatment at the pediatric dentistry clinics and health units in Curitiba, Brazil. To test the instrument's validity, the scores of Brazilian Rapid Estimate of Adult Literacy in Dentistry (BREALD-30) were compared based on occupation, monthly household income, educational attainment, general literacy, use of dental services and three dental outcomes. RESULTS: The BREALD-30 demonstrated good internal reliability. Cronbach's alpha ranged from 0.88 to 0.89 when words were deleted individually. The analysis of test-retest reliability revealed excellent reproducibility (intraclass correlation coefficient = 0.983 and Kappa coefficient ranging from moderate to nearly perfect). In the bivariate analysis, BREALD-30 scores were significantly correlated with the level of general literacy (rs = 0.593) and income (rs = 0.327) and significantly associated with occupation, educational attainment, use of dental services, self-rated oral health and the respondent's perception regarding his/her child's oral health. However, only the association between the BREALD-30 score and the respondent's perception regarding his/her child's oral health remained significant in the multivariate analysis. CONCLUSION: The BREALD-30 demonstrated satisfactory psychometric properties and is therefore applicable to adults in Brazil.

Reliability of self-reported toothbrushing frequency as an indicator for the assessment of oral hygiene in epidemiological research on caries in adolescents: a cross-sectional study.

BACKGROUND: In the present state of knowledge regarding the etiology of dental caries, it is unacceptable for studies addressing factors associated with this outcome to disregard oral hygiene. Simple, valid methods are needed for the assessment of oral hygiene in adolescents to allow this condition to be properly investigated in epidemiological studies on caries and assist in the establishment of health promotion measures. The aim of the present study was to test the hypothesis that the self-reported toothbrushing frequency can be used as a proxy measure for clinical oral hygiene indices in epidemiological studies on dental caries in adolescents. METHODS: A cross-sectional study was conducted with a representative sample (n = 589) of 12-year-old school children in a medium-sized city in southern Brazil. A detailed questionnaire addressing socio-demographic and economic characteristics was sent to primary caregivers. Adolescents answered a brief self-administered questionnaire on behavioral characteristics, including toothbrushing frequency and sugar intake. Samples of stimulated saliva were collected from the adolescents and evaluated for levels of mutans streptococci and lactobacilli using Dentacult kits I and II, respectively. Examiners who had undergone a training and calibration exercise (kappa > 0.81) performed the clinical examination of the adolescents. Caries experience was assessed using the decayed, missing and filled teeth index. Oral hygiene was determined using the Simplified Oral Hygiene Index and the Visible Plaque Index. RESULTS: When the oral hygiene variables were used alone in the multiple models, significant associations with dental caries were found. When Simplified Oral Hygiene Index and/or Plaque Index were used together with toothbrushing frequency in the same model, only the latter was significantly associated with dental caries. A significant association was also found between self-reported toothbrushing frequency and the clinical indices. CONCLUSION: Based on the present findings, self-reported toothbrushing frequency can be used as a proxy measure for clinical oral hygiene indices, which facilitates data collection in epidemiological studies addressing dental caries in adolescents.

Cellular scaling rules for the brain of afrotherians.

Quantitative analysis of the cellular composition of rodent, primate and eulipotyphlan brains has shown that non-neuronal scaling rules are similar across these mammalian orders that diverged about 95 million years ago, and therefore appear to be conserved in evolution, while neuronal scaling rules appear to be free to vary in evolution in a clade-specific manner. Here we analyze the cellular scaling rules that apply to the brain of afrotherians, believed to be the first clade to radiate from the common eutherian ancestor. We find that afrotherians share non-neuronal scaling rules with rodents, primates and eulipotyphlans, as well as the coordinated scaling of numbers of neurons in the cerebral cortex and cerebellum. Afrotherians share with rodents and eulipotyphlans, but not with primates, the scaling of number of neurons in the cortex and in the cerebellum as a function of the number of neurons in the rest of the brain. Afrotheria also share with rodents and eulipotyphlans the neuronal scaling rules that apply to the cerebral cortex. Afrotherians share with rodents, but not with eulipotyphlans nor primates, the neuronal scaling rules that apply to the cerebellum. Importantly, the scaling of the folding index of the cerebral cortex with the number of neurons in the cerebral cortex is not shared by either afrotherians, rodents, or primates. The sharing of some neuronal scaling rules between afrotherians and rodents, and of some additional features with eulipotyphlans and primates, raise the interesting possibility that these shared characteristics applied to the common eutherian ancestor. In turn, the clade-specific characteristics that relate to the distribution of neurons along the surface of the cerebral cortex and to its degree of gyrification suggest that these characteristics compose an evolutionarily plastic suite of features that may have defined and distinguished mammalian groups in evolution.

Oral health-related quality of life among Brazilian dental students.

This study was conducted to assess oral health-related quality of life (OHRQoL) among Brazilian dental students. A cross-sectional study was carried out involving 300 dental students at the Federal University of Parana, Brazil. To measure OHRQoL, the Oral Health Impact Profile (OHIP-14) was self-administered and a questionnaire was filled out addressing socio-demographic characteristics, health-related aspects and dental experience. Descriptive analysis was performed and both univariate and multivariate Poisson regression with robust variance were used to determine associations between OHRQoL and the covariables. The prevalence of reported impact on OHRQoL was 45 percent. The mean OHIP-14 score was 4.5. In the univariate analysis, the reason for the last visit to the dentist (p = 0.004), reported discomfort in teeth/mouth (p < 0.001) and both self-rated general (p = 0.011) and oral (p < 0.001) health were significantly associated with OHRQoL. The year of academic education was not associated with OHRQoL (p = 0.712). In the multivariate model, students who reported dissatisfaction with their teeth (PR = 1.32; IC 95%: 1.01-1.73), dental pain/sensitivity (PR = 2.36; IC 95%: 1.63-3.40), esthetic dental problems (PR = 1.45; IC 95%: 1.10-1.89), restorative needs (PR = 1.60; IC 95%: 1.01-2.55) and whose last visit to the dentist was for curative treatment (PR = 1.36; IC 95%: 1.05-1.76) had greater impact on OHRQoL. Aspects related to previous dental experience and self-reported oral health problems were associated with OHRQoL.

Oral health-related quality of life among Brazilian dental students

This study was conducted to assess oral health-related quality oflife (OHRQoL) among Brazilian dental students. A cross-section-al study was carried out involving 300 dental students at theFederal University of Parana, Brazil. To measure OHRQoL, theOral Health Impact Profile (OHIP-14) was self-administered anda questionnaire was filled out addressing socio-demographiccharacteristics, health-related aspects and dental experience.Descriptive analysis was performed and both univariate and mul-tivariate Poisson regression with robust variance were used todetermine associations between OHRQoL and the covariables.The prevalence of reported impact on OHRQoL was 45 percent.The mean OHIP-14 score was 4.5...

Este estudo teve como objetivo avaliar a qualidade de vidarelacionada à saúde bucal (QVRSB) entre estudantesbrasileiros de odontologia. Um estudo transversal foi realiza-do com 300 estudantes de odontologia da UniversidadeFederal do Paraná, Brasil. Para avaliar a QVRSB, o OralHealth Impact Profile (OHIP-14) foi auto-aplicado juntamentecom um formulário abordando características sócio-demográ-ficas, aspectos relacionados com a saúde e experiênciaodontológica. Foram realizadas análise descritiva, regressãode Poisson univariada e múltipla, com variância robusta, paraverificar possíveis associações entre as covariáveis e aQVRSB. A prevalência de impactos relatados na QVRSB foi de45 por cento...

Oral health-related quality of life among Brazilian dental students

This study was conducted to assess oral health-related quality oflife (OHRQoL) among Brazilian dental students. A cross-section-al study was carried out involving 300 dental students at theFederal University of Parana, Brazil. To measure OHRQoL, theOral Health Impact Profile (OHIP-14) was self-administered anda questionnaire was filled out addressing socio-demographiccharacteristics, health-related aspects and dental experience.Descriptive analysis was performed and both univariate and mul-tivariate Poisson regression with robust variance were used todetermine associations between OHRQoL and the covariables.The prevalence of reported impact on OHRQoL was 45 percent.The mean OHIP-14 score was 4.5...(AU)

Este estudo teve como objetivo avaliar a qualidade de vidarelacionada O saúde bucal (QVRSB) entre estudantesbrasileiros de odontologia. Um estudo transversal foi realiza-do com 300 estudantes de odontologia da UniversidadeFederal do Paraná, Brasil. Para avaliar a QVRSB, o OralHealth Impact Profile (OHIP-14) foi auto-aplicado juntamentecom um formulário abordando características sócio-demográ-ficas, aspectos relacionados com a saúde e experiÛnciaodontológica. Foram realizadas análise descritiva, regressÒode Poisson univariada e múltipla, com variÔncia robusta, paraverificar possíveis associaþ§es entre as covariáveis e aQVRSB. A prevalÛncia de impactos relatados na QVRSB foi de45 por cento...(AU)

Oral health-related quality of life among Brazilian dental students. / Oral health-related quality of life among Brazilian dental students.

This study was conducted to assess oral health-related quality of life (OHRQoL) among Brazilian dental students. A cross-sectional study was carried out involving 300 dental students at the Federal University of Parana, Brazil. To measure OHRQoL, the Oral Health Impact Profile (OHIP-14) was self-administered and a questionnaire was filled out addressing socio-demographic characteristics, health-related aspects and dental experience. Descriptive analysis was performed and both univariate and multivariate Poisson regression with robust variance were used to determine associations between OHRQoL and the covariables. The prevalence of reported impact on OHRQoL was 45 percent. The mean OHIP-14 score was 4.5. In the univariate analysis, the reason for the last visit to the dentist (p = 0.004), reported discomfort in teeth/mouth (p < 0.001) and both self-rated general (p = 0.011) and oral (p < 0.001) health were significantly associated with OHRQoL. The year of academic education was not associated with OHRQoL (p = 0.712). In the multivariate model, students who reported dissatisfaction with their teeth (PR = 1.32; IC 95

: 1.01-1.73), dental pain/sensitivity (PR = 2.36; IC 95

: 1.63-3.40), esthetic dental problems (PR = 1.45; IC 95

: 1.10-1.89), restorative needs (PR = 1.60; IC 95

: 1.01-2.55) and whose last visit to the dentist was for curative treatment (PR = 1.36; IC 95

: 1.05-1.76) had greater impact on OHRQoL. Aspects related to previous dental experience and self-reported oral health problems were associated with OHRQoL.

Nerolidol effects on mitochondrial and cellular energetics.

In the present work, we evaluated the potential toxic effects of nerolidol, a sesquiterpenoid common in plants essential oils, both on mitochondrial and cellular energetics. Samples of enriched natural extracts of nerolidol (a racemic mixture of cis and trans isomers) were tested on rat liver mitochondria and a decrease in phosphorylative system was observed but not in the mitochondrial respiratory chain activity, which reflects a direct effect on F1-ATPase. Hence, respiratory control ratio was also decreased. Cellular ATP/ADP levels were significantly decreased in a concentration-dependent manner, possibly due to the direct effect of nerolidol on F(0)F(1)-ATPsynthase. Nerolidol stimulates respiratory activity probably due to an unspecific effect, since it does not show any protonophoric effect. Furthermore, we observed that mitochondrial permeability transition was delayed in the presence of nerolidol, possibly due to its antioxidant activity and because this compound decreases mitochondrial transmembrane electric potential. Our results also show that, in human hepatocellular liver carcinoma cell line (HepG2), nerolidol both induces cell death and arrests cell growth, probably related with the observed lower bioenergetic efficiency.

"MitoTea": Geranium robertianum L. decoctions decrease blood glucose levels and improve liver mitochondrial oxidative phosphorylation in diabetic Goto-Kakizaki rats.

Several chemical compounds found in plant products have proven to possess beneficial properties, being currently pointed out due to their pharmacological potential in type 2 diabetes mellitus complications. In this context, we studied the effect of Geranium robertianum L. (herb Robert) leaf decoctions in Goto-Kakizaki (GK) rats, a model of type 2 diabetes. Our results showed that oral administration of G. robertianum leaf decoctions over a period of four weeks lowered the plasma glucose levels in diabetic rats. Furthermore, the treatment with G. robertianum extracts improved liver mitochondrial respiratory parameters (state 3, state 4 and FCCP-stimulated respiration) and increased oxidative phosphorylation efficiency.

Hand posture effects on handedness recognition as revealed by the simon effect.

We investigated the influence of hand posture in handedness recognition, while varying the spatial correspondence between stimulus and response in a modified Simon task. Drawings of the left and right hands were displayed either in a back or palm view while participants discriminated stimulus handedness by pressing either a left or right key with their hands resting either in a prone or supine posture. As a control, subjects performed a regular Simon task using simple geometric shapes as stimuli. Results showed that when hands were in a prone posture, the spatially corresponding trials (i.e., stimulus and response located on the same side) were faster than the non-corresponding trials (i.e., stimulus and response on opposite sides). In contrast, for the supine posture, there was no difference between corresponding and non-corresponding trials. Control experiments with the regular Simon task showed that the posture of the responding hand had no influence on performance. When the stimulus is the drawing of a hand, however, the posture of the responding hand affects the spatial correspondence effect because response location is coded based on multiple reference points, including the body of the hand.

Mitochondrial Bioenergetics, Diabetes, and Aging: Top-Down Analysis Using the Diabetic Goto-Kakizaki (GK) Rat as a Model.

In the present study we investigated the changes in the oxidative phosphorylation system of liver mitochondria, isolated from diabetic Goto-Kakizaki (GK) and Wistar (control) rats with different ages (6, 12, 26, and 52 weeks). We used a kinetic approach known as "top-down" analysis, which conceptually divides the oxidative phosphorylation system into two subsystems: one producing the protonmotive force (Deltap) and another that consumes Deltap. The overall response of the Deltap generators to Deltap was obtained from an uncoupler titration of respiration rate versus Deltap, while the overall response of Deltap consumers to Deltap was obtained from an inhibitor titration of respiration rate versus Deltap. Our results showed that GK liver mitochondrial preparations presented an increase in Deltap production and phosphorylative subsystems (using succinate as respiratory substrate). The alterations observed may suggest the existence of biochemical compensatory mechanisms to type 2 diabetes mellitus in GK rats during their first year of life, in order to reduce the injury associated with the disease. Furthermore, we observed that liver metabolic efficiency of mitochondrial respiration declined with age, this decrease in respiratory activity being visible both in control and diabetic rats.

Vitamin E or coenzyme Q10 administration is not fully advantageous for heart mitochondrial function in diabetic goto kakizaki rats.

The heart is one of the organs affected during the later stages of diabetes. Mitochondrial function has already been proposed to be affected during the course of diabetes. Nevertheless, little information is known concerning the impact of antioxidants in heart mitochondria of a milder model for diabetes, such as the Goto-Kakizaki (GK) rat, where mitochondrial function appears ameliorated. The objective of this work was to test if injections of Vitamin E and Coenzyme Q10, alone and in combination, were able to modify mitochondrial performance in the hearts of GK rats. Several aspects of mitochondrial function were measured, such as the respiratory control ratio and the electric potential, as well as the mitochondrial accumulation of Vitamin E and Coenzymes Q9 and Q10. We observed that only Vitamin E appeared to have a positive impact on the mitochondrial phosphorylation efficiency and on mitochondrial performance, namely on the ability to generate the electric transmembrane potential in the presence of supra-physiological calcium concentrations. Vitamin E administration also increased the mitochondrial concentration of Coenzyme Q10. None of the treatments was able to reverse the diabetic phenotype in GK rats. We conclude that in this model of mild hyperglycemia, administration of antioxidants may have a marginal positive impact on mitochondrial function.