AGC1/2, the mitochondrial aspartate-glutamate carriers.

In this review we discuss the structure and functions of the aspartate/glutamate carriers (AGC1-aralar and AGC2-citrin). Those proteins supply the aspartate synthesized within mitochondrial matrix to the cytosol in exchange for glutamate and a proton. A structure of an AGC carrier is not available yet but comparative 3D models were proposed. Moreover, transport assays performed by using the recombinant AGC1 and AGC2, reconstituted into liposome vesicles, allowed to explore the kinetics of those carriers and to reveal their specific transport properties. AGCs participate to a wide range of cellular functions, as the control of mitochondrial respiration, calcium signaling and antioxydant defenses. AGC1 might also play peculiar tissue-specific functions, as it was found to participate to cell-to-cell metabolic symbiosis in the retina. On the other hand, AGC1 is involved in the glutamate-mediated excitotoxicity in neurons and AGC gene or protein alterations were discovered in rare human diseases. Accordingly, a mice model of AGC1 gene knock-out presented with growth delay and generalized tremor, with myelinisation defects. More recently, AGC was proposed to play a crucial role in tumor metabolism as observed from metabolomic studies showing that the asparate exported from the mitochondrion by AGC1 is employed in the regeneration of cytosolic glutathione. Therefore, given the central role of AGCs in cell metabolism and human pathology, drug screening are now being developed to identify pharmacological modulators of those carriers. This article is part of a Special Issue entitled: Mitochondrial Channels edited by Pierre Sonveaux, Pierre Maechler and Jean-Claude Martinou.

Rol de la Ortodoncia y la Ortopedia en el tratamiento de pacientes con traumatismos a nivel dentoalveolar. Reporte de casos / Orthodontics and Orthopedics' role in the treatment of patients with dentoalveoar trauma. Cases reports / O papel da Ortondontía é Ortopedia o pacientes con trauma dentoalveolar. Relato o casos

Se presentan 2 casos clínicos de pacientes con traumatismos dentarios que avalan la importancia de un abordaje multidisciplinario a fin de optimizar su resolución. Se resalta el rol del ortodoncista y el ortopedista dento-máxilo-facial en la prevención, atención adecuada de las diferentes situaciones que pueden presentarse en el transcurso de un traumatismo, y rehabilitación en las diferentes etapas de la dentición, optimizando resultados mediante una fluida interrelación con otros profesionales. Se enfatiza la importancia de que, en la etapa diagnóstica y de planificación de los tratamientos, el profesional sea capaz de detectar secuelas de posibles traumatismos, que de pasar inadvertidos pueden complicar la resolución del caso.

Two clinical cases of dental trauma, showing the importance of the multidisciplinary approach in order to achieve an optimal solution, are presented. Orthodontics and Dento-maxilo-facial Orthopedics' role is emphasized for dentoalveolar injury prevention, proper resolution of different situations in the evolution of a trauma, and optimal treatment outcomes in different dental stages, by means of a fluid communication inside the dental team. It is also extremey important in the diagnosis and treatment planning, that the practitioner be capable to find out possible unnoticed sequelae of trauma that could complicate the case resolution.

Nós apresentamos dois casos de pacientes com traumatismo dentário que suportam a importância de uma abordagem multidisciplinar para otimizar a sua resolução. Ele destaca o papel do ortodontista e ortopedista dento-maxilo-facial na prevenção cuidado adequado das diferentes situações que podem ocorrer durante o trauma e reabilitação em diferentes estágios de dentição otimizando resultados através da interação perfeita com outros profissionais. Ela enfatiza a importancia de que, na avaliação inicial e planejamento do tratamento, o profissional é capaz de detectar as seqüelas de trauma, o que pode complicar despercebido resolver o caso.

Estimation of the Serial Interval for Pandemic Influenza (pH1N1) in the Most Southern Province of Argentina.

BACKGROUND: A retrospective cohort study, in the context of household transmission, to estimate the serial interval (SI) of pH1N1 influenza in the island of Tierra del Fuego was carried out. METHODS: We collected data from the epidemiological surveillance system during disease outbreak in Ushuaia and Rio Grande, the two main cities of the southernmost province of Argentina. Only the records of patients and households with a positive result of RT-PCR assay for pH1N1 virus were used. RESULTS: A total of 283 laboratory confirmed cases were detected, from 550 samples analyzed. Hospitalizations were necessary in 13.8% of patients, yet no deaths were reported. Complete data of household contacts were available in 13 patients. We calculated an SI of 2.0 days (95% CI = 1.5 - 2.6 days), fitting to a log-normal distribution, the one that presented the best adjustment. CONCLUSION: These results were consistent with estimates of SI calculated from Mexico, but lower than estimations from Canada, Germany and USA. We discuss these differences in relation to limitations of the current study design.

A novel method to assist the detection of the Cyclic Alternating Pattern (CAP).

This study proposes a novel method to assist the detection of the components that build up the Cyclic Alternating Pattern (CAP). CAP is a sleep phenomenon formed by consecutive sequences of activations (A1, A2, A3) and non-activations during nonREM sleep. The main importance of CAP evaluation is the possibility of defining the sleep process more accurately. Ten recordings from healthy and good sleepers were included in this study. The method is based on inferential statistics to define the initial and ending points of the CAP components based only on an initialization point given by the expert. The results show concordance up to 95% for A1, 85% for A2 and 60% for A3, together with an overestimation of 1.5 s in A1, 1.3 s in A2 and 0 s in A3. The total CAP rate presents a total underestimation of 7 min. Those results suggest that the method is able to accurately detect the initial and ending points of the activations, and may be helpful for the physicians by reducing the time dedicated to the manual inspection task.

PP65 antigenemia in the diagnosis of cytomegalovirus infection in AIDS patients

Cytomegalovirus causes significant morbidity and mortality in AIDS patients and those having undergone bone marrow or another transplant. PP65 antigenemia is based on detecting viral antigen in peripheral blood leukocytes through immunochemistry and by monitoring the infection in immunocompromised individuals. The present study aimed to set up this diagnostic technique in AIDS patients with active cytomegalovirus infection and verify its occurrence in the Botucatu region of São Paulo state, Brazil. Fifty patients, 35 men and 15 women aged from 24 to 69 years, were recruited from those attended at the Department of Tropical Diseases of Botucatu Medical School, UNESP, and divided into three groups according to CD4+ T lymphocyte counts and antiretroviral treatment. The control group comprised bone marrow transplant patients. Fourteen AIDS patients with low CD4+ cell counts tested positive for PP65 antigenemia, which could predict cytomegalovirus infection and indicate prophylactic treatment.

PP65 antigenemia in the diagnosis of cytomegalovirus infection in AIDS patients

Cytomegalovirus causes significant morbidity and mortality in AIDS patients and those having undergone bone marrow or another transplant. PP65 antigenemia is based on detecting viral antigen in peripheral blood leukocytes through immunochemistry and by monitoring the infection in immunocompromised individuals. The present study aimed to set up this diagnostic technique in AIDS patients with active cytomegalovirus infection and verify its occurrence in the Botucatu region of São Paulo state, Brazil. Fifty patients, 35 men and 15 women aged from 24 to 69 years, were recruited from those attended at the Department of Tropical Diseases of Botucatu Medical School, UNESP, and divided into three groups according to CD4+ T lymphocyte counts and antiretroviral treatment. The control group comprised bone marrow transplant patients. Fourteen AIDS patients with low CD4+ cell counts tested positive for PP65 antigenemia, which could predict cytomegalovirus infection and indicate prophylactic treatment.(AU)

Antigen-specific T-cell responses of leprosy patients.

The identification of human T-cell antigens of Mycobacterium leprae could improve treatment and help to disrupt the transmission of leprosy by directing diagnosis and vaccine programs. This study screened a panel of M. leprae recombinant proteins for T-cell recall responses, measured by gamma interferon (IFN-gamma) production, among leprosy patients. After initial studies using peripheral blood mononuclear cells from leprosy patients, we transitioned our studies to simple whole-blood assays (WBA), which are more applicable in field or clinical settings. T-cell responses generated in WBA using blood from individuals in Goiânia, Brazil, demonstrated that several M. leprae antigens (ML0276, ML0840, ML1623, ML2044, and 46f) elicited >0.5 IU/ml IFN-gamma, and these proteins were classified as immunogenic and leprosy specific. Several of these individual antigens were recognized by cells from >60% of Brazilian paucibacillary (PB) leprosy patients, and ML0276, ML0840, ML1623, and 46f complemented each other such that 82% of PB patients had strong (>1.25 IU/ml IFN-gamma) responses to at least one of these proteins. These proteins were also recognized by cells from a significant proportion of the household contacts of multibacillary leprosy patients, but in contrast, few responses were observed in active tuberculosis patients or healthy control groups from areas of endemicity. Our results indicate several potential candidate antigens which may be useful for either leprosy diagnosis or vaccination and demonstrate the utility of leprosy WBA that can be applied broadly in clinical or field settings.

Cardiac and vascular effects of diltiazem, dobutamine and amrinone, drugs used after myocardial revascularization.

Hemodynamic care during postoperative management of myocardial revascularization should include vasorelaxing drugs to insure adequate graft and coronary flow, and stimulation of stroke volume to maintain vascular perfusion pressure. We tested the cardiac (inotropic and lusitropic) and vascular (relaxant) effects of diltiazem (0.1 nM to 0.1 mM), dobutamine (10 microM to 10 mM) and amrinone (10 microM to 1 mM) on isolated rat atria and thoracic aorta, and also on isolated human saphenous vein (HSV) and human mammary artery (HMA). Dobutamine produced a maximal positive inotropic effect (+dF/dt max = 29 +/- 7%) at its ED50 for aortic relaxation (88 +/- 7 microM). Conversely, at their ED50 for aortic relaxation diltiazem depressed myocardial contractility and amrinone did not exhibit myocardial effects. In HSV and HMA contracted with 80 mM potassium, diltiazem and dobutamine (but not amrinone) had a vasorelaxant activity similar to that in rat aorta. Norepinephrine-contracted human vessels were significantly more sensitive than potassium-contracted vessels to the relaxant effect of amrinone (ED50 HMA = 15 +/- 5 microM, ED50 HSV = 72 +/- 31 microM, P < 0.05). We conclude that at concentrations still devoid of myocardial effects dobutamine and amrinone are effective dilators in graft segment vessels and rat aorta contracted by membrane depolarization. If the difference between aortic and myocardial tissue still holds in human tissues, at the appropriate concentrations these drugs should be expected to improve cardiac performance while still contributing to the maintenance of graft patency.

Cardiac and vascular effects of diltiazem, dobutamine and amrinone, drugs used after myocardial revascularization

Hemodynamic care during postoperative management of myocardial revascularization should include vasorelaxing drugs to insure adequate graft and coronary flow, and stimulation of stroke volume to maintain vascular perfusion pressure. We tested the cardiac (inotropic and lusitropic) and vascular (relaxant) effects of diltiazem (0.1 nM to 0.1 mM), dobutamine (10 æM to 10 mM) and amrinone (10 æM to 1 mM) on isolated rat atria and thoracic aorta, and also on isolated human saphenous vein (HSV) and human mammary artery (HMA). Dobutamine produced a maximal positive inotropic effect (+dF/dt max = 29 ñ 7 percent) at its ED50 for aortic relaxation (88 ñ 7 æM). Conversely, at their ED50 for aortic relaxation diltiazem depressed myocardial contractility and amrinone did not exhibit myocardial effects. In HSV and HMA contracted with 80 mM potassium, diltiazem and dobutamine (but not amrinone) had a vasorelaxant activity similar to that in rat aorta. Norepinephrine-contracted human vessels were significantly more sensitive than potassium-contracted vessels to the relaxant effect of amrinone (ED50 HMA = 15 ñ 5 æM, ED50 HSV = 72 ñ 31 æM, P < 0.05). We conclude that at concentrations still devoid of myocardial effects dobutamine and amrinone are effective dilators in graft segment vessels and rat aorta contracted by membrane depolarization. If the difference between aortic and myocardial tissue still holds in human tissues, at the appropriate concentrations these drugs should be expected to improve cardiac performance while still contributing to the maintenance of graft patency.

Short-term streptozotocin-induced diabetes induces blood pressure decrease associated with reduced aortic (45)Ca(2+) uptake and selective depression of the sustained noradrenergic contraction.

To test the hypothesis that diabetes can selectively affect the intracellular and extracellular components of the noradrenergic vascular response in rats, we studied changes in blood pressure, in vitro vascular contraction and (45) Ca(2+) uptake in experimental diabetes induced by injection of 60 mg/kg of streptozotocin (STZ). One week after induction of diabetes mean blood pressure decreased significantly from 106 +/- 3 mmHg to 89 +/- 2 mmHg. After incubation in Ca(2+) =1.6 mM, contraction of STZ aortic rings to 10(- 7) M of norepinephrine was preserved in its intracellular component (Control: 231 +/- 28, STZ: 274 +/- 22 mgForce/mgTissue, NS) but depressed in its extracellular component (Control: 277 +/- 24, STZ: 133 +/- 33 mgForce/mgTissue, P<0.05). Uptake of (45) Ca(2+) in the same rings was depressed in both components. Norepinephrine contractions due to extracellular Ca(2+) (prior depletion of norepinephrine-sensitive Ca(2+) stores) unexpectedly exhibited a initial component whose magnitude in control rings was similar to the response due to intracellular Ca(2+) (extra: 503 +/- 65 mg, intra: 411 +/- 30 mgForce/mgTissue), and was not depressed in STZ preparations (399 +/- 62 mgForce/mgTissue). The sustained contraction to norepinephrine in extracellular Ca(2+) was significantly reduced in STZ aortas (1163 +/- 92 vs. 528 +/- 95 mgForce/mgTissue). We conclude that: 1) Short-term streptozotocin-induced diabetes features reduced blood pressure along with deficient aortic (45) Ca uptake and contraction to norepinephrine, and 2) Only the sustained phase of the norepinephrine contraction, dependent on extracellular Ca(2+), was depressed in the diabetic rats and could possibly be associated with the observed fall in blood pressure.

Mechanical properties of human saphenous veins from normotensive and hypertensive patients.

BACKGROUND: Different reactivities of saphenous vein grafts in hypertensive and normotensive patients could lead to differences in the postoperative patency of the grafts. METHODS: In saphenous vein rings isolated from remnants of aorta-coronary grafts obtained from hypertensive and normotensive patients we studied the length-tension relationship; response to high levels of potassium, norepinephrine, and epinephrine; and relaxation in response to calcium deprivation. RESULTS: The rings from hypertensive patients were stiffer and developed more force (grams force/grams weight) than the rings from normotensive subjects to 80 mmol/L potassium (59+/-16 versus 25+/-5, p < 0.05) and to 1 micromol/L norepinephrine (61+/-8 versus 36+/-7, p < 0.05), but not to 10 micromol/L epinephrine (57+/-11 and 54+/-11; not significant). The rings from hypertensive patients relaxed more slowly than those of the normotensive subjects in a calcium-free medium (time to half-relaxation of 976+/-180 versus 548+/-81 seconds; p < 0.05). CONCLUSIONS: The saphenous vein from hypertensive patients is less distensible, slower to relax, and more reactive to at least two agonists. These differences could influence the graft's patency and the clinical outcome.

Chronotropic, inotropic and lusitropic effects of capsaicin on isolated rat atria.

This work includes results on chronotropic, inotropic and lusitropic changes induced by capsaicin on isolated rat atria. As regards spontaneous frequency, it was stimulated from 10(-9) M up to 7 x 10(-7) M of capsaicin. A simultaneous depression in developed force (F) showed a significant correlation with this positive chronotropic effect up to 7 x 10(-8) M of capsaicin, which is the result of the negative staircase phenomenon in the rat heart. The correlation was lost at 2 and 7 x 10(-7) M of capsaicin since in spite of the sustained increase in atrial rate the decrease in F was reversed and then depressed again at 2 and 7 x 10(-6) M of capsaicin without changes in frequency. A concentration of capsaicin that overcome the negative staircase phenomenon, 5 x 10(-7) M, was tested as unique dose resulting in stimulation of the chronotropic, inotropic and lusitropic states of the atria. Percentual differences with respect to control values were maximal after 1-3 minutes for frequency (10 +/- 3%), F (29 +/- 4%), maximal velocity of force development (+F = 50 +/- 12%) (in all cases +F and -F bold indicates +F and -F, respectively), and maximal velocity of relaxation (-F = 64 +/- 13%); a positive lusitropic effect was significant after 8-10 minutes (+F/-F = 17 +/- 7%). Capsaicin did not affect the rat atria in the presence of 10(-6) M of ruthenium red, a blocker of capsaicin activation of sensory nerves, indicating that the stimulatory effects were entirely mediated by the release of neurotransmitters and that this concentration of capsaicin was not deleterous "per se". Capsaicin elicited similar inotropic responses in electrically driven isolated atria (+F = 41 +/- 9%) but the positive lusitropic effect was lost suggesting that capsaicin-induced increases in -F are limited at a frequency higher than the spontaneous frequency (11 +/- 6 vs. 32 +/- 4%, respectively). 10(-6) M of CGRP8-37, an antagonist of CGRP1 receptors, suppress the stimulatory effects of capsaicin on atrial contraction. In summary, atrial rate as compared to atrial contraction is more sensitive to the neurotransmitter released by capsaicin, which results in mechanical effects expressing the negative staircase phenomenon in the rat at low concentrations of capsaicin. The positive chronotropic, inotropic and lusitropic responses elicited by capsaicin are mediated by the release of neurotransmitters from sensory fibbers and no deletereous effects of capsaicin "per se" became evident when the release of neuropeptides was prevented. Atrial contraction was depressed at higher capsaicin concentrations than the one showing stimulatory effects. Stimulation of atrial contractility is mediated by activation of CGRP receptors.

[Effect of insulin on contractile response and calcium binding in rat aorta]. / Efectos de la insulina sobre la respuesta contráctil y la captación de calcio en aorta de rata.

UNLABELLED: Insulin affects physiological mechanisms involved in blood pressure regulation, and at the cellular level modifies endothelial and vascular smooth muscle functions underlying the changes in peripheral resistance. We describe the effects of preincubation with insulin (40 microU/ml for 1-2 hs) on the contractile reactivity of intact rat aortic rings and on 45Ca2+ uptake of EGTA-hyperpermeabilized rat aortic segments. Preincubation with insulin did not affect either contractions induced by 1 microM of NA, or their relaxation induced by 10 mM of caffeine. The contractile response to 1 microM of Ang-II (which in rat aorta is endothelium-independent) was stimulated by insulin preincubation resulting in increases of both maximal developed force and velocity of its spontaneous relaxation. The difference in 45Ca2+ uptake between insulin-treated and insulin-untreated aortic segments was greater at 5 minutes than it was at 30 minutes. CONCLUSIONS: Insulin preincubation affects directly the mechanical response of Ang-II stimulated aortic smooth muscle; we suggest that the modification of SR function is one of the mechanisms involved in insulin regulation of cytosolic Ca2+.

[Insulin, vascular reactivity and hypertension]. / Insulina, reactividad vascular e hipertensión arterial.

Several epidemiological studies have shown that there is a relationship between hyperinsulinemia, insulin resistance and arterial hypertension. Insulin produces sympathetic nervous system stimulation, enhances renal sodium retention and it directly modifies vascular mechanisms involved in both contraction and relaxation of the vascular smooth muscle. These actions of insulin could lead either to elevation or reduction of blood pressure. The absence of vasodilation due to insulin resistance and/or the enhancement of the hypertensive effects due to hyperinsulinemia could be the link between insulin and hypertension.

Two-compartment gentamicin pharmacokinetics in premature neonates: a comparison to adults with decreased glomerular filtration rates.

Eleven premature neonates received gentamicin sulfate for treatment of suspected gram-negative sepsis with accompanying respiratory distress syndrome. Serum gentamicin concentrations were measured during and after treatment to monitor therapy and to determine the two-compartment distribution and elimination characteristics of the drug. The measured pharmacolinetic parameters were compared to those of 14 adult patients with similar glomerular filtration rates. Neonates, like adults and children, had a prolonged persistence of gentamicin in the serum after treatment was stopped. Although there were marked differences between neonates and adults in administered dose, clearance, and distribution volume when the data were expressed on the basis of body weight, these differences were no longer apparent when the data were expressed relative to body surface area. Differences in gentamicin disposition cannot explain the apparent lack of aminoglycoside nephrotoxicity among premature neonates.