Influence of Nitric Oxide-Cyclic GMP and Oxidative STRESS on Amyloid-ß Peptide Induced Decrease of Na,K-ATPase Activity in Rat Hippocampal Slices.

Amyloid-ß peptide (Aß) has been shown to cause synaptic dysfunction and can render neurons vulnerable to excitotoxicity and oxidative stress. Na,K-ATPase plays an important role to maintain cell ionic equilibrium and it can be modulated by N-methyl-D-aspartate (NMDA)-nitric oxide (NO)-cyclic GMP pathway. Disruption of NO synthase (NOS) activity and reactive oxygen species (ROS) production could lead to changes in Na,K-ATPase isoforms' activities that may be detrimental to the cells. Our aim was to evaluate the signaling pathways of Aß in relation to NMDA-NOS-cyclic GMP versus oxidative stress on α1-/α2,3-Na,K-ATPase activities in rat hippocampal slices. Aß1-40 induced a concentration-dependent increase of NOS activity and increased cyclic guanosine monophosphate (cGMP), TBARS (thiobarbituric acid reactive substances), and 3-Nitrotyrosine (3-NT)-modified protein levels in rat hippocampal slices. The increase in NOS activity and cyclic GMP levels induced by Aß1-40 was completely blocked by MK-801 (inhibitor of NMDA receptor) and L-NAME (inhibitor of NOS) pre-treatment but changes in TBARS levels were only partially blocked by both compounds. The Aß treatment also decreased Na,K-ATPase activity which was reverted by N-nitro-L-arginine methyl ester hydrochloride (L-NAME) but not by MK-801 pre-treatment. The decrease in enzyme activity induced by Aß was isoform-specific since only α1-Na,K-ATPase was affected. These findings suggest that the activation of NMDA-NOS signaling cascade linked to α2,3-Na,K-ATPase activity may mediate an adaptive, neuroprotective response to Aß in rat hippocampus.

Performance strategies affect mammary gland development in prepubertal heifers.

In Brazil, the majority of dairy cattle are Holstein × Gyr (H×G). It is unknown whether excessive energy intake negatively affects their mammary development to the same extent as in purebred Holsteins. We hypothesized that mammary development of H×G heifers can be affected by dietary energy supply. We evaluated the effect of different average daily gains (ADG) achieved by feeding different amounts of a standard diet during the growing period on biometric measurements, development of mammary parenchyma (PAR) and mammary fat pad (MFP), and blood hormones. At the outset of this 84-d experiment, H×G heifers (n = 18) weighed 102.2 ± 3.4 kg and were 3 to 4 mo of age. Heifers were randomly assigned to 1 of 3 ADG programs using a completely randomized design. Treatments were high gain (HG; n = 6), where heifers were fed to gain 1 kg/d; low gain (LG; n = 6), where heifers were fed to gain 0.5 kg/d; and maintenance (MA; n = 6), where heifers were fed to gain a minimal amount of weight per day. Heifers were fed varying amounts of a single TMR to support desired BW gains. Over the 84 d, periodic biometric and blood hormone measurements were obtained. On d 84, all heifers were slaughtered and carcass and mammary samples were collected. At the end, HG heifers weighed the most (181 ± 7.5 kg), followed by LG (146 ± 7.5 kg) and MA (107 ± 7.5 kg) heifers. The ADG were near expected values and averaged 0.907, 0.500, and 0.105 ± 0.03 kg/d for HG, LG, and MA, respectively. In addition, body lengths, heart girths, and withers heights were affected by dietary treatment, with MA heifers generally being the smallest and HG heifers generally being the largest. Body condition scores differed by treatment and were highest in HG and lowest in MA heifers; in vivo subcutaneous fat thickness measurement and direct analysis of carcass composition supported this. The HG heifers had the heaviest MFP, followed by LG and then MA heifers. Amount of PAR was highest in LG heifers and was the same for HG and MA heifers. The percentage of udder mass occupied by PAR was lowest in HG heifers, differing from LG and MA heifers. Composition of MFP was not evaluated. Regarding PAR composition, no differences in ash or DM were found. On the other hand, CP concentration of PAR for HG heifers was lower than that for LG heifers, which was lower than that for MA heifers. Regarding the fat content, HG treatment was higher than LG and MA treatment, which did not differ from each other. In PAR, differences in relative abundance of genes related to both stimulation and inhibition of mammary growth were observed to depend on dietary treatment, sampling day, or both. The same can be said for most of the blood hormones that were measured in this experiment. In this experiment, high ADG achieved by feeding different amounts of a standard diet during the growing period negatively affected mammary development.

Coreceptor usage by HIV-1 and HIV-2 primary isolates: the relevance of CCR8 chemokine receptor as an alternative coreceptor.

The human immunodeficiency virus replication cycle begins by sequential interactions between viral envelope glycoproteins with CD4 molecule and a member of the seven-transmembrane, G-protein-coupled, receptors' family (coreceptor). In this report we focused on the contribution of CCR8 as alternative coreceptor for HIV-1 and HIV-2 isolates. We found that this coreceptor was efficiently used not only by HIV-2 but particularly by HIV-1 isolates. We demonstrate that CXCR4 usage, either alone or together with CCR5 and/or CCR8, was more frequently observed in HIV-1 than in HIV-2 isolates. Directly related to this is the finding that the non-usage of CXCR4 is significantly more common in HIV-2 isolates; both features could be associated with the slower disease progression generally observed in HIV-2 infected patients. The ability of some viral isolates to use alternative coreceptors besides CCR5 and CXCR4 could further impact on the efficacy of entry inhibitor therapy and possibly also in HIV pathogenesis.

[Hypoglycaemia without ketosis. A case report]. / Hipoglucemia sin cetosis. Caso clínico.

INTRODUCTION: Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) is a rare disease, inherited as autosomal-recessive trait, with variable clinical presentation including severe hypoglycaemia, cardiomyopathy, sudden infant death, progressive liver failure, 'Reye like' syndrome, neuromyopathy, muscle weakness and rhabdomyolysis. CASE REPORT: We report a 3 years old male patient admitted to our emergency department with vomiting, hypotonia and prostration, after a common respiratory infection. The presence of hypoketotic hypoglycaemia and elevated liver enzymes in the admission motivated a metabolic study. We found an abnormal low lactate/pyruvate ratio, decreased serum carnitine and dicarboxylic aciduria leading to the diagnosis of a fatty acid oxidation disorder (LCHADD). The molecular study of HADHA gene revealed homozygosity for the G1528C mutation in the patient DNA, and heterozygosity in both parents. CONCLUSIONS: The diagnosis of a fatty acid oxidation disorder must be considered in the presence of vomiting associated with excessive prostration specially if there is hypoketotic hypoglycaemia or familiar sudden infant death history. Physicians should be aware about these conditions and for the importance of measuring both glycaemia and ketone bodies during the evaluation of high risk situations.

Hipoglucemia sin cetosis. Caso clínico / Hypoglycaemia without ketosis. A case report

Introducción. La deficiencia de 3-hidroxiacil-CoA deshidrogenasa de cadena larga (LCHADD) es una enfermedad metabólica muy poco frecuente, de transmisión autosómica recesiva con expresión variable, que incluye la hipoglucemia grave, cardiomiopatía y posible muerte súbita infantil, fallo hepático progresivo, síndrome de Reye-like, déficit neurosensoriales, debilidad muscular y rabdomiólisis. Caso clínico. Niño de 3 años que llegó al servicio de urgencias con un cuadro de vómitos, disminución del nivel de conciencia e hipotonía, en el contexto de una infección respiratoria sin gravedad. El estudio analítico reveló hipoglucemia no cetósica y citólisis hepática, lo cual motivó la realización de un estudio metabólico. Se constató una disminución de la relación lactato/piruvato, hipocarnitinemia y aciduria dicarboxílica, y el perfil de los ácidos orgánicos urinarios resultó compatible con el déficit de β-oxidación, más específicamente LCHADD. El estudió genético mostró la mutación G1528C, en el gen HADHA, en homocigosis en la sangre del niño y en heterocigosis en los dos progenitores, lo cual confirmó el diagnóstico. Conclusiones. El diagnóstico de déficit de b-oxidación se debe plantear en presencia de vómitos asociados a postración desproporcionada o letargia, especialmente si se confirma hipoglucemia hipocetósica o historia familiar de muerte súbita. Es importante la sensibilización y alerta sobre la existencia de estas patologías, especialmente en lo que se refiere a la importancia del registro de la glucemia y cuerpos cetónicos urinarios en la evaluación de las situaciones de riesgo (AU)

Introduction. Long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD) is a rare disease, inherited as autosomal- recessive trait, with variable clinical presentation including severe hypoglycaemia, cardiomyopathy, sudden infant death, progressive liver failure, ‘Reye like’ syndrome, neuromyopathy, muscle weakness and rhabdomyolysis. Case report. We report a 3 years old male patient admitted to our emergency department with vomiting, hypotonia and prostration, after a common respiratory infection. The presence of hypoketotic hypoglycaemia and elevated liver enzymes in the admission motivated a metabolic study. We found an abnormal low lactate/pyruvate ratio, decreased serum carnitine and dicarboxylic aciduria leading to the diagnosis of a fatty acid oxidation disorder (LCHADD). The molecular study of HADHA gene revealed homozygosity for the G1528C mutation in the patient DNA, and heterozygosity in both parents. Conclusions. The diagnosis of a fatty acid oxidation disorder must be considered in the presence of vomiting associated with excessive prostration specially if there is hypoketotic hypoglycaemia or familiar sudden infant death history. Physicians should be aware about these conditions and for the importance of measuring both glycaemia and ketone bodies during the evaluation of high risk situations (AU)

Potential utility of random amplified polymorphic DNA (RAPD) and restriction endonuclease assay (REA) as typing systems for Madurella mycetomatis.

Two molecular methods were compared, random amplified polymorphic DNA (RAPD) and restriction endonuclease analysis (REA), in order to evaluate their ability to discriminate, and to characterize Madurella mycetomatis strains isolated from human mycetomas in different parts of the world. Both methods were able to cluster the Madurella mycetomatis isolates into the same number of distinct typing groups. However, RAPD, presenting several advantages over REA such as its rapidity, simplicity, and the accessibility for implementation in the laboratory, is a more sensitive and reproducible tool for the study of Madurella mycetomatis epidemiology than REA.

The effect of a re-wetting agent on dentin bonding.

OBJECTIVES: Recently, a new generation of simplified one-bottle dentin bonding systems, sensitive to variations in the degree of substrate moisture, was introduced. This in vitro project compared the dentin bond strengths and interfacial ultra-morphology formed by three one-bottle bonding systems [OptiBond SOLO (ethanol-based), Prime&Bond 2.1 (acetone-based), and Single Bond (ethanol- and water-based)]. The null hypothesis tested was that re-wetting a dried dentin surface with a HEMA aqueous solution would not result in bond strengths, and resin impregnation into demineralized dentin, comparable to those obtained for moist dentin. METHODS: Dentin specimens were assigned to the following three etched surface conditions: moist dentin-control group; dentin dried for 5 s; and dentin dried for 5 s and re-moistened with a commercial 35% HEMA aqueous solution. Mean shear bond strengths were calculated and analyzed with one- and two-way ANOVA. Dentin discs treated with the same combination of surface condition/adhesive were processed and observed under both transmission and scanning electron microscopes. RESULTS: For moist dentin, the morphology of the resin-dentin interfaces showed penetration of the dentin adhesives to the depth of the transition between demineralized and unaffected dentin. Drying dentin for 5 s resulted in a significant decrease in mean bond strengths and an incompletely infiltrated collagen structure with areas of unveiled collagen fibers, regardless of the solvent. Re-wetting dentin with the aqueous HEMA solution re-established the level of bond strengths obtained to moist dentin and resulted in a raise of the fiber network with simultaneous increase in interfibrillar space dimensions. SIGNIFICANCE: The results suggest that the use of an aqueous HEMA solution might compensate for the dryness induced on dentin surfaces by using air blasts from an air syringe, after rinsing off the etchant. As the behavior of the material that contained water was also affected by surface dryness, the percentage of water included in the composition of current ethanol- and water-based adhesives, such as Single Bond, may not be enough to compensate for the collapse of the collagen filigree upon drying.

[Assessment of the left ventricular function in patients with pacemakers VVI and DDD, using non-invasive methods (systolic time)]. / Avaliação da função ventricular esquerda em doentes portadores de Pacemakers VVI e DDD, por métodos não invasivos (tempos sistólicos).

OBJECTIVE: Determination of left ventricular function, in patients with ventricular inhibited (VVI) and atrioventricular universal (DDD) pacemakers, by measurement of systolic time intervals. DESIGN: Twenty six patients were studied (six with DDD pacemakers and twenty with VVI pacemakers). In all of them systolic time intervals measurements were obtained the day before and one week after the implant. PATIENTS: We have studied twenty six patients consecutively, and all of them completed the study. INTERVENTIONS: The measurement of systolic time intervals was obtained, by the simultaneous recording of ECG, phonocardiogram and carotid arterial pulse. The recordings were obtained at a paper speed of 100 mm/sec. MEASUREMENTS AND RESULTS: The values obtained before the implantation were similar in both groups, but one week after implantation they show a closer to normal ventricular function, in patients with DDD pacemakers. CONCLUSIONS: The measurements of systolic time intervals, is a very easy method, to determine left ventricular function non invasively. In patients with DDD pacemakers, the left ventricular function, was better than in patients with VVI pacemakers.

[Alcohol and the heart]. / Alcool e coração.

Alcohol, above certain levels in blood, becomes a depressor of myocardial fiber. Excessive intake of alcoholic drinks is responsible for disrhythmias, congestive heart failure, thromboembolic phenomena and, sometimes, sudden death. Dilated cardiomyopathy is the usual clinical presentation of these patients. More than 60 gr daily of ethanol may be an important factor in the etiology of high blood pressure. Yet, not everything is negative as far as alcohol and heart are concerned. Moderate consumption of ethanol decrease the risk of coronary heart disease, but, regarding the medical and social implications of alcoholic habits, they shall not be encouraged. Finally, it must be emphasized that in cases of disrhythmias, hypertension and deteriorated left ventricular function (ejection fraction below 35%) the use of alcoholic beverages must strongly discouraged. The same applies to patients taking anticoagulants or sedative drugs.

Cisto mucoso do osso (cisto osseo justa-articular). Apresentacao de um caso com lesoes multiplas. / Mucous bone cyst (juxta - articular bone cyst). Report of a case with multiple lesions

Os autores apresentam um caso de lesao cistica, multifocal, de conteudo mucoso, que ocorreu em paciente do sexo masculino de 32 anos de idade.Revisam a bibliografia pertinente ao assunto e discutem a nomenclatura, propondo o nome de cisto mucoso do osso