Prolonged culture of human pancreatic islets under glucotoxic conditions changes their acute beta cell calcium and insulin secretion glucose response curves from sigmoid to bell-shaped.

AIMS/HYPOTHESIS: The rapid remission of type 2 diabetes by a diet very low in energy correlates with a marked improvement in glucose-stimulated insulin secretion (GSIS), emphasising the role of beta cell dysfunction in the early stages of the disease. In search of novel mechanisms of beta cell dysfunction after long-term exposure to mild to severe glucotoxic conditions, we extensively characterised the alterations in insulin secretion and upstream coupling events in human islets cultured for 1-3 weeks at ~5, 8, 10 or 20 mmol/l glucose and subsequently stimulated by an acute stepwise increase in glucose concentration. METHODS: Human islets from 49 non-diabetic donors (ND-islets) and six type 2 diabetic donors (T2D-islets) were obtained from five isolation centres. After shipment, the islets were precultured for 3-7 days in RPMI medium containing ~5 mmol/l glucose and 10% (vol/vol) heat-inactivated FBS with selective islet picking at each medium renewal. Islets were then cultured for 1-3 weeks in RPMI containing ~5, 8, 10 or 20 mmol/l glucose before measurement of insulin secretion during culture, islet insulin and DNA content, beta cell apoptosis and cytosolic and mitochondrial glutathione redox state, and assessment of dynamic insulin secretion and upstream coupling events during acute stepwise stimulation with glucose [NAD(P)H autofluorescence, ATP/(ATP+ADP) ratio, electrical activity, cytosolic Ca2+ concentration ([Ca2+]c)]. RESULTS: Culture of ND-islets for 1-3 weeks at 8, 10 or 20 vs 5 mmol/l glucose did not significantly increase beta cell apoptosis or oxidative stress but decreased insulin content in a concentration-dependent manner and increased beta cell sensitivity to subsequent acute stimulation with glucose. Islet glucose responsiveness was higher after culture at 8 or 10 vs 5 mmol/l glucose and markedly reduced after culture at 20 vs 5 mmol/l glucose. In addition, the [Ca2+]c and insulin secretion responses to acute stepwise stimulation with glucose were no longer sigmoid but bell-shaped, with maximal stimulation at 5 or 10 mmol/l glucose and rapid sustained inhibition above that concentration. Such paradoxical inhibition was, however, no longer observed when islets were acutely depolarised by 30 mmol/l extracellular K+. The glucotoxic alterations of beta cell function were fully reversible after culture at 5 mmol/l glucose and were mimicked by pharmacological activation of glucokinase during culture at 5 mmol/l glucose. Similar results to those seen in ND-islets were obtained in T2D-islets, except that their rate of insulin secretion during culture at 8 and 20 mmol/l glucose was lower, their cytosolic glutathione oxidation increased after culture at 8 and 20 mmol/l glucose, and the alterations in GSIS and upstream coupling events were greater after culture at 8 mmol/l glucose. CONCLUSIONS/INTERPRETATION: Prolonged culture of human islets under moderate to severe glucotoxic conditions markedly increased their glucose sensitivity and revealed a bell-shaped acute glucose response curve for changes in [Ca2+]c and insulin secretion, with maximal stimulation at 5 or 10 mmol/l glucose and rapid inhibition above that concentration. This novel glucotoxic alteration may contribute to beta cell dysfunction in type 2 diabetes independently from a detectable increase in beta cell apoptosis.

Interception and early treatment with rapid maxillary expansion for the impacted maxillary permanent central incisor in children: Two cases report with 5-years follow-up.

INTRODUCTION: The maxillary central incisor impaction represents a complex challenge in paediatric dentistry practice and may result in aesthetic and functional disharmony. The causes of this condition include physical barriers associated or not with a lack of space making eruption not possible, idiopathic ectopic positioning of the teeth or by trauma, non-coordination in rhizalysis and rhizogenesis between deciduous and successor or tooth shape abnormalities. The incidence of this involvement is quite rare, around 1% of the population. Opening of space through disjunction of the palatal suture is the main treatment proposed to solve this situation and, when necessary, the orthodontic traction assisted by surgery. DESCRIPTION: Were presented two cases of maxillary central incisors impaction in children treated with rapid maxillary expansion, alignment and levelling, and a follow-up after 5 years of treatment. RESULTS AND CONCLUSIONS: The challenge of these treatments were based on the early treatment in mixed dentition with expansion. The treatment of permanent maxillary central incisor impaction in children enabled excellent periodontal response and post-treatment occlusal stability.

Criocirurgia intralesional em lesões vasculares benignas: boa opção para angioma rubi e hamartomas sobre mancha vinho do Porto / Intralesional cryosurgery in benign vascular lesions: a good option for cherry angioma and hamartomas over port-wine stain

A criocirurgia é uma técnica de vasto conhecimento e uso entre dermatologistas. A aplicação intralesional já é utilizada no tratamento de queloides e tem como vantagem restringir a zona de ação das baixas temperaturas do nitrogênio líquido. O uso da criocirurgia de contato em lesões vasculares é relatado, mas não há publicações sobre a técnica intralesional nesses tipos de lesões. Aqui, relatamos dois casos: 1- Hamartomas sobre mancha vinho do Porto em um paciente de 61 anos; e 2 - Angioma rubi em um paciente de 70 anos, ambos tratados de forma satisfatória e segura com criocirurgia intralesional.

Cryosurgery is a technique widely known and used among dermatologists. Intralesional application is already used to treat keloids and has the advantage of restricting the zone of action of low temperatures of liquid nitrogen. The use of contact cryosurgery in vascular lesions is well reported in the literature, but there are no intralesional technique publications on these types of lesions. Here, we report two cases, one of port-wine stain hamartomas in a 61-year-old patient and another of a cherry angioma in a 70-year-old patient, safely and satisfactorily treated with intralesional cryosurgery

Role of cytochrome P450-derived, polyunsaturated fatty acid mediators in diabetes and the metabolic syndrome.

Over the last decade, cases of metabolic syndrome and type II diabetes have increased exponentially. Exercise and ω-3 polyunsaturated fatty acid (PUFA)-enriched diets are usually prescribed but no therapy is effectively able to restore the impaired glucose metabolism, hypertension, and atherogenic dyslipidemia encountered by diabetic patients. PUFAs are metabolized by different enzymes into bioactive metabolites with anti- or pro-inflammatory activity. One important class of PUFA metabolizing enzymes are the cytochrome P450 (CYP) enzymes that can generate a series of bioactive products, many of which have been attributed protective/anti-inflammatory and insulin-sensitizing effects in animal models. PUFA epoxides are, however, further metabolized by the soluble epoxide hydrolase (sEH) to fatty acid diols. The biological actions of the latter are less well understood but while low concentrations may be biologically important, higher concentrations of diols derived from linoleic acid and docosahexaenoic acid have been linked with inflammation. One potential application for sEH inhibitors is in the treatment of diabetic retinopathy where sEH expression and activity is elevated as are levels of a diol of docosahexaenoic acid that can induce the destabilization of the retina vasculature.

Short-term high glucose culture potentiates pancreatic beta cell function.

The exposure of pancreatic islets to high glucose is believed to be one of the causal factors of the progressive lowering of insulin secretion in the development of type 2 diabetes. The progression of beta cell failure to type 2 diabetes is preceded by an early positive increase in the insulin secretory response to glucose, which is only later followed by a loss in the secretion capacity of pancreatic islets. Here we have investigated the electrophysiological mechanisms underlying the early glucose-mediated gain of function. Rodent pancreatic islets or dispersed islet cells were cultured in medium containing either 5.6 (control) or 16.7 (high-glucose) mM glucose for 24 h after isolation. Glucose-stimulated insulin secretion was enhanced in a concentration-dependent manner in high glucose-cultured islets. This was associated with a positive effect on beta cell exocytotic capacity, a lower basal KATP conductance and a higher glucose sensitivity to fire action potentials. Despite no changes in voltage-gated Ca2+ currents were observed in voltage-clamp experiments, the [Ca2+]I responses to glucose were drastically increased in high glucose-cultured cells. Of note, voltage-dependent K+ currents were decreased and their activation was shifted to more depolarized potentials by high-glucose culture. This decrease in voltage-dependent K+ channel (Kv) current may be responsible for the elevated [Ca2+]I response to metabolism-dependent and independent stimuli, associated with more depolarized membrane potentials with lower amplitude oscillations in high glucose-cultured beta cells. Overall these results show that beta cells improve their response to acute challenges after short-term culture with high glucose by a mechanism that involves modulation not only of metabolism but also of ion fluxes and exocytosis, in which Kv activity appears as an important regulator.

Glucolipotoxic conditions induce ß-cell iron import, cytosolic ROS formation and apoptosis.

Type 2 diabetes (T2D) arises when the pancreatic beta-cell fails to compensate for increased insulin needs due to insulin resistance. Glucolipotoxicity (GLT) has been proposed to induce beta-cell dysfunction in T2D by formation of reactive oxygen species (ROS). Here, we examined if modeling glucolipotoxic conditions by high glucose-high free fatty acid (FFA) exposure (GLT) regulates beta-cell iron transport, by increasing the cytosolic labile iron pool (LIP). In isolated mouse islets, the GLT-induced increase in the LIP catalyzed cytosolic ROS formation and induced apoptosis. We show that GLT-induced ROS production is regulated by an increased LIP associated with elevated expression of genes regulating iron import. Using pharmacological and transgenic approaches, we show that iron reduction and decreased iron import protects from GLT-induced ROS production, prevents impairment of the mitochondrial membrane potential (MMP) and inhibits apoptosis. This study identifies a novel pathway underlying GLT-induced apoptosis involving increased iron import, generation of hydroxyl radicals from hydrogen peroxide through the Fenton reaction in the cytosolic compartment associated with dissipation of the MMP and beta-cell apoptosis.

NNT reverse mode of operation mediates glucose control of mitochondrial NADPH and glutathione redox state in mouse pancreatic ß-cells.

OBJECTIVE: The glucose stimulation of insulin secretion (GSIS) by pancreatic ß-cells critically depends on increased production of metabolic coupling factors, including NADPH. Nicotinamide nucleotide transhydrogenase (NNT) typically produces NADPH at the expense of NADH and ΔpH in energized mitochondria. Its spontaneous inactivation in C57BL/6J mice was previously shown to alter ATP production, Ca2+ influx, and GSIS, thereby leading to glucose intolerance. Here, we tested the role of NNT in the glucose regulation of mitochondrial NADPH and glutathione redox state and reinvestigated its role in GSIS coupling events in mouse pancreatic islets. METHODS: Islets were isolated from female C57BL/6J mice (J-islets), which lack functional NNT, and genetically close C57BL/6N mice (N-islets). Wild-type mouse NNT was expressed in J-islets by adenoviral infection. Mitochondrial and cytosolic glutathione oxidation was measured with glutaredoxin 1-fused roGFP2 probes targeted or not to the mitochondrial matrix. NADPH and NADH redox state was measured biochemically. Insulin secretion and upstream coupling events were measured under dynamic or static conditions by standard procedures. RESULTS: NNT is largely responsible for the acute glucose-induced rise in islet NADPH/NADP+ ratio and decrease in mitochondrial glutathione oxidation, with a small impact on cytosolic glutathione. However, contrary to current views on NNT in ß-cells, these effects resulted from a glucose-dependent reduction in NADPH consumption by NNT reverse mode of operation, rather than from a stimulation of its forward mode of operation. Accordingly, the lack of NNT in J-islets decreased their sensitivity to exogenous H2O2 at non-stimulating glucose. Surprisingly, the lack of NNT did not alter the glucose-stimulation of Ca2+ influx and upstream mitochondrial events, but it markedly reduced both phases of GSIS by altering Ca2+-induced exocytosis and its metabolic amplification. CONCLUSION: These results drastically modify current views on NNT operation and mitochondrial function in pancreatic ß-cells.

NADPH oxidase-2 does not contribute to ß-cell glucotoxicity in cultured pancreatic islets from C57BL/6J mice.

High glucose-induced oxidative stress and increased NADPH oxidase-2 (NOX2) activity may contribute to the progressive decline of the functional ß-cell mass in type 2 diabetes. To test that hypothesis, we characterized, in islets from male NOX2 knockout (NOX2-KO) and wild-type (WT) C57BL/6J mice cultured for up to 3 weeks at 10 or 30 mmol/l glucose (G10 or G30), the in vitro effects of glucose on cytosolic oxidative stress using probes sensing glutathione oxidation (GRX1-roGFP2), thiol oxidation (roGFP1) or H2O2 (roGFP2-Orp1), on ß-cell stimulus-secretion coupling events and on ß-cell apoptosis. After 1-2 days of culture in G10, the glucose stimulation of insulin secretion (GSIS) was ∼1.7-fold higher in NOX2-KO vs. WT islets at 20-30 mmol/l glucose despite similar rises in NAD(P)H and intracellular calcium concentration ([Ca2+]i) and no differences in cytosolic GRX1-roGFP2 oxidation. After long-term culture at G10, roGFP1 and roGFP2-Orp1 oxidation and ß-cell apoptosis remained low, and the glucose-induced rises in NAD(P)H, [Ca2+]i and GSIS were similarly preserved in both islet types. After prolonged culture at G30, roGFP1 and roGFP2-Orp1 oxidation increased in parallel with ß-cell apoptosis, the glucose sensitivity of the NADPH, [Ca2+]i and insulin secretion responses increased, the maximal [Ca2+]i response decreased, but maximal GSIS was preserved. These responses were almost identical in both islet types. In conclusion, NOX2 is a negative regulator of maximal GSIS in C57BL/6J mouse islets, but it does not detectably contribute to the in vitro glucotoxic induction of cytosolic oxidative stress and alterations of ß-cell survival and function.

Estudo epidemiológico de vítimas de queimaduras internadas em um hospital de urgência da Bahia / Epidemiological study of victims of injured burns in an emergency hospital of Bahia / Estudio epidemiológico de las víctimas de quemaduras ingresado en un hospital de emergencia de Bahia

OBJETIVO: Identificar as características epidemiológicas de pacientes vítimas de queimaduras internados em um Centro de Tratamento de Queimaduras da Bahia. MÉTODO: Estudo epidemiológico retrospectivo, transversal, realizado em um hospital público de referência em queimaduras. Foram incluídos 112 pacientes adultos e idosos de ambos os sexos, por amostragem de conveniência, vítimas de qualquer tipo de queimadura. A amostra foi caracterizada quanto ao sexo, idade, comorbidades, à profundidade, localização, etiologia e extensão da superfície corporal queimada (SCQ). RESULTADOS: A maioria dos pacientes avaliados era do sexo masculino (58,9%, n=66), adultos (91,9%, n=103) e idosos (8,1%, n=9), previamente hígidos (77,7%, n=87) e entre aqueles com comorbidades, 21,4% (n=24) eram hipertensos e 6,3% (n=7) diabéticos. Cerca de 50% (n=53) dos pacientes tinham queimadura em graus diferentes, atingindo até 10% de SCQ. O principal agente etiológico foi queimadura por líquido quente (66%, n=74), com maior prevalência nos membros superiores (70,5%, n=79), seguida da região da cabeça (46,4%, n=52) e membros inferiores (45,5%, n=51). CONCLUSÃO: Houve predomínio de pacientes adultos, do sexo masculino, previamente hígidos, com queimadura de segundo grau, decorrente de algum líquido, acometendo principalmente os membros superiores e atingindo até 10% da SCQ. Programas educacionais contínuos em prol da prevenção são necessários, pois muitos acidentes com queimaduras poderiam ser evitados.

OBJECTIVE: To identify the epidemiological characteristics of patients who are victims of burns hospitalized at a Burn Treatment Center in Bahia. METHODS: Retrospective, cross-sectional epidemiological study conducted at a public hospital burn reference. We included 112 adult and elderly patients of both sexes, by convenience sampling, victims of any type of burn. The sample was characterized by sex, age, comorbidities, depth, location, etiology and extent of burned body surface (BBS). RESULTS: The majority of the patients were male (58.9%, n=66), adults (91.9%, n=103) and elderly (8.1%, n=9), previously healthy (77.7%, n=87) and among those with comorbidities, 21.4% (n=24) were hypertensive and 6.3% (n=7) were diabetic. About 50% (n=53) of the patients had burns in different degrees, reaching up to 10% BBS. The main etiological agent was hot liquid burn (66%, n=74), with a higher prevalence in the upper limbs (70.5%, n=79) followed by the head region (46.4%, n=52) and lower limbs (45.5%, n=51). CONCLUSION: There was a predominance of adult, male patients, previously healthy, with second degree burns, due to some liquid, mainly affecting the upper limbs and reaching up to 10% of SCQ. Continued educational programs for prevention are needed, as many accidents with burns could be avoided.

Objetivo: Identificar las características epidemiológicas de las víctimas de quemaduras ingresados en un Centro de Tratamiento de Quemaduras de Bahía. Método: Estudio epidemiológico transversal, retrospectivo, realizado en un hospital público de referencia para las quemaduras. Se incluyeron 112 pacientes adultos y ancianos de ambos sexos, para la muestra de conveniencia, víctimas de cualquier tipo de quemadura. La muestra se caracterizó cuanto al género, la edad, comorbilidades, la profundidad, la ubicación, la etiología y la extensión de la superficie corporal quemada (SCQ). Resultados: La mayoría de los pacientes eran hombres (58,9%, n=66), adultos (91,9%, n=103) y ancianos (8,1%, n=9), previamente sanos (77,7%, n=87) y entre aquellos con comorbilidades, 21,4% (n=24) eran hipertensos 6,3% (n=7) y diabéticos. Aproximadamente el 50% (n=53) de los pacientes tenían quemaduras en distintos grados, alcanzando el 10% de SCQ. El principal agente etiológico fue quemada por el líquido caliente (66%, n=74), con la más alta prevalencia en las extremidades superiores (70,5%, n=79), seguido por la región de la cabeza (46,4%, n=52) y las extremidades inferiores (45,5%, n=51). Conclusión: Se encontró un predominio de pacientes adultos, varón, previamente sano, con quemadura de segundo grado, derivado de cualquier líquido, que afecta principalmente a las extremidades superiores y hasta el 10% de la SCQ. Se necesitan programas educativos continuos para la prevención, porque muchos accidentes con quemaduras podrían evitarse.

The soluble epoxide hydrolase determines cholesterol homeostasis by regulating AMPK and SREBP activity.

Inhibition or deletion of the soluble epoxide hydrolase (sEH) has been linked to reduced cholesterol and protection against atherosclerosis. This study set out to identify sEH substrate(s) or product(s), altered in livers from sEH(-/-) mice that contribute to these beneficial effects. In livers and isolated hepatocytes, deletion of sEH decreased expression of HMG CoA reductase, fatty acid synthase and low density lipoprotein receptor. Sterol regulatory element binding proteins (SREBPs) regulate the expression of all three enzymes and SREBP activation was attenuated in the absence of sEH. The effect was attributed to the AMPK-activated protein kinase (AMPK) which was activated in the absence of sEH. Livers from wild-type versus sEH(-/-) littermates contained significantly higher levels of the sEH substrate 12,13-epoxyoctadecenoic acid, which elicited AMPK activation, while the corresponding sEH product was inactive. Thus, AMPK activation and subsequent inhibition of SREBP can account for the altered expression of lipid metabolizing enzymes in sEH(-/-) mice.

Effect of the suture technique on postoperative pain, swelling and trismus after removal of lower third molars: a randomized clinical trial

BACKGROUND: To evaluate the intensity of pain, swelling and trismus after the removal of impacted lower third molars comparing two different suture techniques of the triangular flap: the complete suture of the distal incision and relieving incision and the partial suture with only one suture knot for closure of the corner of the flap and the closure of the distal incision, without suturing the relieving incision. MATERIAL AND METHODS:A prospective, randomized, cross-over clinical trial was conducted in 40 patients aged from 18 to 45 years who underwent surgical extraction of impacted lower third molars at the Department of Oral Surgery in the Odontological Hospital of the University of Barcelona during the year 2011. Patients were randomly divided in 2 groups. Two different techniques (hermetical closure and partial closure of the wound) were performed separated by a one month washout period in each patient. Postoperative pain, swelling and trismus were evaluated prior to the surgical procedure and also at 2 and 7 days postoperatively. RESULTS: No statistically significant differences were observed for pain (p<0.06), trismus (p<0.71) and swelling (p<0.05) between the test and the control group. However, the values of the three parameters related to the test group were lower than those for the control group. CONCLUSIONS: Partial closure of the flap without suturing the relieving incision after surgical extraction of lower third molars reduces operating time and it does not produce any postoperative complications compared with complete closure of the wound

Effect of the suture technique on postoperative pain, swelling and trismus after removal of lower third molars: A randomized clinical trial.

BACKGROUND: To evaluate the intensity of pain, swelling and trismus after the removal of impacted lower third molars comparing two different suture techniques of the triangular flap: the complete suture of the distal incision and relieving incision and the partial suture with only one suture knot for closure of the corner of the flap and the closure of the distal incision, without suturing the relieving incision. MATERIAL AND METHODS: A prospective, randomized, cross-over clinical trial was conducted in 40 patients aged from 18 to 45 years who underwent surgical extraction of impacted lower third molars at the Department of Oral Surgery in the Odontological Hospital of the University of Barcelona during the year 2011. Patients were randomly divided in 2 groups. Two different techniques (hermetical closure and partial closure of the wound) were performed separated by a one month washout period in each patient. Postoperative pain, swelling and trismus were evaluated prior to the surgical procedure and also at 2 and 7 days postoperatively. RESULTS: No statistically significant differences were observed for pain (p<0.06), trismus (p<0.71) and swelling (p<0.05) between the test and the control group. However, the values of the three parameters related to the test group were lower than those for the control group. CONCLUSIONS: Partial closure of the flap without suturing the relieving incision after surgical extraction of lower third molars reduces operating time and it does not produce any postoperative complications compared with complete closure of the wound.

Unveiling a common mechanism of apoptosis in ß-cells and neurons in Friedreich's ataxia.

Friedreich's ataxia (FRDA) is a neurodegenerative disorder associated with cardiomyopathy and diabetes. Effective therapies for FRDA are an urgent unmet need; there are currently no options to prevent or treat this orphan disease. FRDA is caused by reduced expression of the mitochondrial protein frataxin. We have previously demonstrated that pancreatic ß-cell dysfunction and death cause diabetes in FRDA. This is secondary to mitochondrial dysfunction and apoptosis but the underlying molecular mechanisms are not known. Here we show that ß-cell demise in frataxin deficiency is the consequence of oxidative stress-mediated activation of the intrinsic pathway of apoptosis. The pro-apoptotic Bcl-2 family members Bad, DP5 and Bim are the key mediators of frataxin deficiency-induced ß-cell death. Importantly, the intrinsic pathway of apoptosis is also activated in FRDA patients' induced pluripotent stem cell-derived neurons. Interestingly, cAMP induction normalizes mitochondrial oxidative status and fully prevents activation of the intrinsic pathway of apoptosis in frataxin-deficient ß-cells and neurons. This preclinical study suggests that incretin analogs hold potential to prevent/delay both diabetes and neurodegeneration in FRDA.

Acute nutrient regulation of the mitochondrial glutathione redox state in pancreatic ß-cells.

The glucose stimulation of insulin secretion by pancreatic ß-cells depends on increased production of metabolic coupling factors, among which changes in NADPH and ROS (reactive oxygen species) may alter the glutathione redox state (EGSH) and signal through changes in thiol oxidation. However, whether nutrients affect EGSH in ß-cell subcellular compartments is unknown. Using redox-sensitive GFP2 fused to glutaredoxin 1 and its mitochondria-targeted form, we studied the acute nutrient regulation of EGSH in the cytosol/nucleus or the mitochondrial matrix of rat islet cells. These probes were mainly expressed in ß-cells and reacted to low concentrations of exogenous H2O2 and menadione. Under control conditions, cytosolic/nuclear EGSH was close to -300 mV and unaffected by glucose (from 0 to 30 mM). In comparison, mitochondrial EGSH was less negative and rapidly regulated by glucose and other nutrients, ranging from -280 mV in the absence of glucose to -299 mV in 30 mM glucose. These changes were largely independent from changes in intracellular Ca(2+) concentration and in mitochondrial pH. They were unaffected by overexpression of SOD2 (superoxide dismutase 2) and mitochondria-targeted catalase, but were inversely correlated with changes in NAD(P)H autofluorescence, suggesting that they indirectly resulted from increased NADPH availability rather than from changes in ROS concentration. Interestingly, the opposite regulation of mitochondrial EGSH and NAD(P)H autofluorescence by glucose was also observed in human islets isolated from two donors. In conclusion, the present study demonstrates that glucose and other nutrients acutely reduce mitochondrial, but not cytosolic/nuclear, EGSH in pancreatic ß-cells under control conditions.

[Evaluation of surgical training in medical school]. / Avaliação de treinamento cirúrgico na graduação de medicina.

OBJECTIVE: To evaluate the effectiveness of training in surgical techniques in pig feet during medical school. METHODS: We conducted a cross-sectional study with 87 volunteer medical students from different graduation semesters, who attended a basic workshop for incisions, sutures, biopsies, flaps, grafts, under direct supervision. Pre and post-training self-administered questionnaires were used. RESULTS: The teaching of sutures, biopsies and ear correction was effective for learning of the minimal skills required for the proposed techniques (p <0.005), as well as excisions and flaps, except grafting (p> 0 97). CONCLUSION: The methodological approach and monitoring of techniques' reproduction were adequate. The training offered complemented cutaneous surgical skills of undergraduate medicine students.

Avaliação de treinamento cirúrgico na graduação de medicina / Evaluation of surgical training in medical school

OBJETIVO: Avaliar a efetividade de um treinamento de técnicas cirúrgicas em pata de porco durante a graduação em medicina. MÉTODOS: Estudo transversal com 87 acadêmicos de medicina voluntários, provenientes de diferentes períodos da graduação, que participaram de uma oficina básica para realização de incisões, suturas, biópsias, retalhos, enxertos, sob supervisão direta. Foram utilizados questionários autoaplicáveis pré e pós-treinamento. RESULTADOS: O ensino de suturas, biópsias e correção de orelha mostrou-se efetivo para o aprendizado de habilidades mínimas exigidas para as técnicas propostas (p<0,005), bem como, das excisões e retalhos exercitados, à exceção do enxerto (p>0,97). CONCLUSÃO: A abordagem metodológica e o monitoramento de reprodução das técnicas mostraram-se adequados. O treinamento oferecido complementou as habilidades cirúrgicas cutâneas dos graduandos de medicina.

OBJECTIVE: To evaluate the effectiveness of training in surgical techniques in pig feet during medical school. METHODS: We conducted a cross-sectional study with 87 volunteer medical students from different graduation semesters, who attended a basic workshop for incisions, sutures, biopsies, flaps, grafts, under direct supervision. Pre and post-training self-administered questionnaires were used. RESULTS: The teaching of sutures, biopsies and ear correction was effective for learning of the minimal skills required for the proposed techniques (p <0.005), as well as excisions and flaps, except grafting (p> 0 97). CONCLUSION: The methodological approach and monitoring of techniques' reproduction were adequate. The training offered complemented cutaneous surgical skills of undergraduate medicine students.

Dual effect of advanced glycation end products in pancreatic islet apoptosis.

BACKGROUND: Loss of ß-cell function hastens deterioration of metabolic control in type 2 diabetes patients. Besides amyloid deposit and glucolipotoxicity, advanced glycation end products (AGEs) acting through their receptors (RAGE) seem to contribute to this process by promoting islet apoptosis. In order to investigate the role of AGEs in ß-cell deterioration, we evaluated the temporal and dose effects of AGE compounds on apoptosis rate, reactive oxygen species generation and expression of pro-apoptotic and anti-apoptotic genes in cultured islets. METHODS: Rat pancreatic islets were exposed or not for 24, 48, 72 and 96 h to albumin modified by glycoaldehyde. Apoptosis, reactive oxygen species and superoxide content and NADPH oxidase activity were evaluated as well as RNA expression of the genes Ager (codes for RAGE), Bax, Bcl2 and Nfkb1. RESULTS: In 24 and 48 h, glycoaldehyde elicited a decrease in apoptosis rate in comparison with the control condition concomitantly with a reduction in Bax/Bcl2 RNA ratio and in Nfkb1 RNA expression. In contrast, after 72 and 96 h, glycoaldehyde promoted an increase in apoptosis rate concomitantly with an increase in Bax/Bcl2 RNA ratio and in Nfkb1 RNA expression. In 24 h, glycoaldehyde elicited a decrease in the islet content of reactive oxygen species, whereas after 48 and 72 h, it promoted an opposite effect, increasing superoxide generation. The NADPH oxidase inhibitor VAS2870 attenuated superoxide production, implicating NADPH oxidase as an important source of reactive oxygen species in islets exposed to AGEs. CONCLUSIONS: Albumin modified by glycoaldehyde exerted a dual effect in cultured pancreatic islets, being protective against apoptosis after short exposure but pro-apoptotic after prolonged exposure.

Antioxidant defenses and biochemical changes in the neotropical fish pacu, Piaractus mesopotamicus: responses to single and combined copper and hypercarbia exposure.

This study investigated the potentially detrimental effects of copper and elevated aquatic CO(2) (hypercarbia), alone or in combination, on pacu, Piaractus mesopotamicus. Fish were exposed for 48 h to control (no copper addition in normocarbia), to 400 µg Cu(2+)L(-1), to hypercarbic (1% CO(2); PCO(2) = 6.9 mm Hg) water and to 400 µg Cu(2+)L(-1) + hypercarbia. In liver the single factors caused an increase in lipid hydroperoxide concentration that was not observed when the factors were combined. Copper exposure elicited increased hepatic superoxide dismutase activity, irrespective of aquatic CO(2) level. On the other hand, the effects of copper on hepatic glutathione peroxidase activity were dependent on water CO(2) levels. The two stressors combined did not affect hepatic catalase activity. Hypercarbic water caused a decline in plasma glucose concentration, but this was not observed when hypercarbia was combined with copper exposure. Copper caused a decrease in branchial Na(+)/K(+)-ATPase activity that was independent of water CO(2) level. Copper caused an increase in branchial metallothionein concentration that was independent of water CO(2) level. Thus, branchial metallothionein and Na(+)/K(+)-ATPase were effective biomarkers of copper exposure that were not affected by water CO(2) level.

Potential contribution of translational factors to triiodo-L-thyronine-induced insulin synthesis by pancreatic beta cells.

BACKGROUND: Thyroid hormones (THs) are known to regulate protein synthesis by acting at the transcriptional level and inducing the expression of many genes. However, little is known about their role in protein expression at the post-transcriptional level, even though studies have shown enhancement of protein synthesis associated with mTOR/p70S6K activation after triiodo-L-thyronine (T3) administration. On the other hand, the effects of TH on translation initiation and polypeptidic chain elongation factors, being essential for activating protein synthesis, have been poorly explored. Therefore, considering that preliminary studies from our laboratory have demonstrated an increase in insulin content in INS-1E cells in response to T3 treatment, the aim of the present study was to investigate if proteins of translational nature might be involved in this effect. METHODS: INS-1E cells were maintained in the presence or absence of T3 (10(-6) or 10(-8) M) for 12 hours. Thereafter, insulin concentration in the culture medium was determined by radioimmunoassay, and the cells were processed for Western blot detection of insulin, eukaryotic initiation factor 2 (eIF2), p-eIF2, eIF5A, EF1A, eIF4E binding protein (4E-BP), p-4E-BP, p70S6K, and p-p70S6K. RESULTS: It was found that, in parallel with increased insulin generation, T3 induced p70S6K phosphorylation and the expression of the translational factors eIF2, eIF5A, and eukaryotic elongation factor 1 alpha (eEF1A). In contrast, total and phosphorylated 4E-BP, as well as total p70S6K and p-eIF2 content, remained unchanged after T3 treatment. CONCLUSIONS: Considering that (i) p70S6K induces S6 phosphorylation of the 40S ribosomal subunit, an essential condition for protein synthesis; (ii) eIF2 is essential for the initiation of messenger RNA translation process; and (iii) eIF5A and eEF1A play a central role in the elongation of the polypeptidic chain during the transcripts decoding, the data presented here lead us to suppose that a part of T3-induced insulin expression in INS-1E cells depends on the protein synthesis activation at the post-transcriptional level, as these proteins of the translational machinery were shown to be regulated by T3.

Maternal melatonin programs the daily pattern of energy metabolism in adult offspring.

BACKGROUND: Shift work was recently described as a factor that increases the risk of Type 2 diabetes mellitus. In addition, rats born to mothers subjected to a phase shift throughout pregnancy are glucose intolerant. However, the mechanism by which a phase shift transmits metabolic information to the offspring has not been determined. Among several endocrine secretions, phase shifts in the light/dark cycle were described as altering the circadian profile of melatonin production by the pineal gland. The present study addresses the importance of maternal melatonin for the metabolic programming of the offspring. METHODOLOGY/PRINCIPAL FINDINGS: Female Wistar rats were submitted to SHAM surgery or pinealectomy (PINX). The PINX rats were divided into two groups and received either melatonin (PM) or vehicle. The SHAM, the PINX vehicle and the PM females were housed with male Wistar rats. Rats were allowed to mate and after weaning, the male and female offspring were subjected to a glucose tolerance test (GTT), a pyruvate tolerance test (PTT) and an insulin tolerance test (ITT). Pancreatic islets were isolated for insulin secretion, and insulin signaling was assessed in the liver and in the skeletal muscle by western blots. We found that male and female rats born to PINX mothers display glucose intolerance at the end of the light phase of the light/dark cycle, but not at the beginning. We further demonstrate that impaired glucose-stimulated insulin secretion and hepatic insulin resistance are mechanisms that may contribute to glucose intolerance in the offspring of PINX mothers. The metabolic programming described here occurs due to an absence of maternal melatonin because the offspring born to PINX mothers treated with melatonin were not glucose intolerant. CONCLUSIONS/SIGNIFICANCE: The present results support the novel concept that maternal melatonin is responsible for the programming of the daily pattern of energy metabolism in their offspring.