Effects of hypertonic sodium chloride solution on the electrophysiologic alterations caused by bupivacaine in the dog heart

The effects of various hypertonic solutions on the intraventricular conduction, ventricular repolarization and the arrhythmias caused by the intravenous (iv) injection of bupivacaine (6.5 mg/kg) were studied in sodium pentobarbital-anesthetized mongrel dogs. Hypertonic solutions, given iv 5 min before bupivacaine, were 7.5% (w/v) NaCl, 5.4% (w/v) LiCl, 50% (w/v) glucose (2,400 mOsm/l, 5 ml/kg), or 20% (w/v) mannitol (1,200 mOsm/l, 10 ml/kg). Bupivacaine induced severe arrhythmias and ventricular conduction and repolarization disturbances, as reflected by significant increases in QRS complex duration, HV interval, IV interval and monophasic action potential duration, as well as severe hemodynamic impairment. Significant prevention against ventricular electrophysiologic and hemodynamic disturbances and ventricular arrhythmias was observed with 7.5% NaCl (percent increase in QRS complex duration: 164.4 ± 21.8% in the non-pretreated group vs 74.7 ± 14.1% in the pretreated group, P<0.05; percent increase in HV interval: 131.4 ± 16.1% in the non-pretreated group vs 58.2 ± 7.5% in the pretreated group, P<0.05; percent increase in monophasic action potential duration: 22.7 ± 6.8% in the non-pretreated group vs 9.8 ± 6.3% in the pretreated group, P<0.05; percent decrease in cardiac index: -46 ± 6% in the non-pretreated group vs -28 ± 5% in the pretreated group, P<0.05). The other three hypertonic solutions were ineffective. These findings suggest an involvement of sodium ions in the mechanism of hypertonic protection.

Role of nitric oxide of the median preoptic nucleus (MnPO) in the alterations of salivary flow, arterial pressure and heart rate induced by injection of pilocarpine into the MnPO and intraperitoneally

We investigated the effect of L-NAME, a nitric oxide (NO) inhibitor and sodium nitroprusside (SNP), an NO-donating agent, on pilocarpine-induced alterations in salivary flow, mean arterial blood pressure (MAP) and heart rate (HR) in rats. Male Holtzman rats (250-300 g) were implanted with a stainless steel cannula directly into the median preoptic nucleus (MnPO). Pilocarpine (10, 20, 40, 80, 160 µg) injected into the MnPO induced an increase in salivary secretion (P<0.01). Pilocarpine (1, 2, 4, 8, 16 mg/kg) ip also increased salivary secretion (P<0.01). Injection of L-NAME (40 µg) into the MnPO prior to pilocarpine (10, 20, 40, 80, 160 µg) injected into the MnPO or ip (1, 2, 4, 8, 16 mg/kg) increased salivary secretion (P<0.01). SNP (30 µg) injected into the MnPO or ip prior to pilocarpine attenuated salivary secretion (P<0.01). Pilocarpine (40 µg) injection into the MnPO increased MAP and decreased HR (P<0.01). Pilocarpine (4 mg/kg body weight) ip produced a decrease in MAP and an increase in HR (P<0.01). Injection of L-NAME (40 µg) into the MnPO prior to pilocarpine potentiated the increase in MAP and reduced HR (P<0.01). SNP (30 µg) injected into the MnPO prior to pilocarpine attenuated (100%) the effect of pilocarpine on MAP, with no effect on HR. Administration of L-NAME (40 µg) into the MnPO potentiated the effect of pilocarpine injected ip. SNP (30 µg) injected into the MnPO attenuated the effect of ip pilocarpine on MAP and HR. The present study suggests that in the rat MnPO 1) NO is important for the effects of pilocarpine on salivary flow, and 2) pilocarpine interferes with blood pressure and HR (side effects of pilocarpine), that is attenuated by NO.

Nocardia otitidiscaviarum (GAM-5) induces parkinsonian-like alterations in mouse

Parkinson's disease, a major neurodegenerative disorder in humans whose etiology is unknown, may be associated with some environmental factors. Nocardia otitidiscaviarum (GAM-5) isolated from a patient with an actinomycetoma produced signs similar to Parkinson's disease following iv injection into NMRI mice. NMRI mice were infected intravenously with a non-lethal dose of 5 x 10(6) colony forming units of N. otitidiscaviarum (GAM-5). Fourteen days after bacterial infection, most of the 60 mice injected exhibited parkinsonian features characterized by vertical head tremor, akinesia/bradykinesia, flexed posture and postural instability. There was a peak of nocardial growth in the brain during the first 24 h followed by a decrease, so that by 14 days nocardiae could no longer be cultured. At 24 h after infection, Gram staining showed nocardiae in neurons in the substantia nigra and occasionally in the brain parenchyma in the frontal and parietal cortex. At 21 days post-infection, tyrosine hydroxylase immunolabeling showed a 58% reduction of tyrosine hydroxylase in the substantia nigra, and a 35% reduction of tyrosine hydroxylase in the ventral tegmental region. Dopamine levels were reduced from 110 ± 32.5 to 58 ± 16.5 ng/mg protein (47.2% reduction) in brain from infected mice exhibiting impaired movements, whereas serotonin levels were unchanged (191 ± 44 protein in control and 175 ± 39 ng/mg protein in injected mice). At later times, intraneuronal inclusion bodies were observed in the substantia nigra. Our observations emphasize the need for further studies of the potential association between Parkinson's disease or parkinsonism-like disease and exposure to various nocardial species.

Morphological and functional alterations of the intestine of rats with iron-deficiency anemia

The present study was designed to assess the intestinal absorption of D-xylose and jejunal morphometry in rats with iron-deficiency anemia. Male Wistar rats were randomly divided into a control group (diet containing 50 mg Fe/kg, N = 12) and an anemic group (diet containing <5 mg Fe/kg, N = 12). The animals were housed in individual metabolic cages and deionized water and diet were provided ad libitum for 6 weeks. Hemoglobin and hematocrit were determined at 0, 2, 4, and 6 weeks. At the end of the study the rats were submitted to a D-xylose absorption test (50 mg/100 g body weight) and sacrificed and a jejunal specimen was obtained for morphometric study. At the end of the study the hemoglobin and hematocrit of the anemic rats (8.7 ± 0.9 g/dl and 34.1 ± 2.9%, respectively) were significantly (P < 0.05) lower than those of the controls (13.9 ± 1.4 g/dl and 47.1 ± 1.5%, respectively). There was no statistical difference in D-xylose absorption between the anemic (46.5 ± 7.4%) and control (43.4 ± 9.0%) groups. The anemic animals presented statistically greater villus height (445.3 ± 36.8 µm), mucosal thickness (614.3 ± 56.3 µm) and epithelial surface (5063.0 ± 658.6 µm) than control (371.8 ± 34.3, 526.7 ± 62.3 and 4401.2 ± 704.4 µm, respectively; P < 0.05). The increase in jejunum villus height, mucosal thickness and epithelial surface in rats with iron-deficiency anemia suggests a compensatory intestinal mechanism to increase intestinal iron absorption.

Rarity of DNA sequence alterations in the promoter region of the human androgen receptor gene

The human androgen receptor (AR) gene promoter lies in a GC-rich region containing two principal sites of transcription initiation and a putative Sp1 protein-binding site, without typical "TATA" and "CAAT" boxes. It has been suggested that mutations within the 5'untranslated region (5'UTR) may contribute to the development of prostate cancer by changing the rates of gene transcription and/or translation. In order to investigate this question, the aim of the present study was to search for the presence of mutations or polymorphisms at the AR-5'UTR in 92 prostate cancer patients, where histological diagnosis of adenocarcinoma was established in specimens obtained from transurethral resection or after prostatectomy. The AR-5'UTR was amplified by PCR from genomic DNA samples of the patients and of 100 healthy male blood donors, included as controls. Conformation-sensitive gel electrophoresis was used for DNA sequence alteration screening. Only one band shift was detected in one individual from the blood donor group. Sequencing revealed a new single nucleotide deletion (T) in the most conserved portion of the promoter region at position +36 downstream from the transcription initiation site I. Although the effect of this specific mutation remains unknown, its rarity reveals the high degree of sequence conservation of the human androgen promoter region. Moreover, the absence of detectable variation within the critical 5'UTR in prostate cancer patients indicates a low probability of its involvement in prostate cancer etiology.

Effect of iron overload on the severity of liver histologic alterations and on the response to interferon and ribavirin therapy of patients with hepatitis C infection

The objective of the present study was to determine the presence of hepatic iron overload in patients with chronic HCV infection and to correlate it with histologic alterations, HCV genotype and response to therapy. Liver tissue samples from 95 patients with chronic hepatitis C were divided into two groups: group I, presence of iron overload in hepatic tissue (Perls' staining) and group II, no iron overload. Hepatic iron overload was detected in 30 (31.6%) of 95 patients. Of the 69 patients tested by genotyping, 49 (71.01%) were genotype 1 and 20 (28.99%) genotype non-1. Iron overload was detected in 14 (28.6%) patients with genotype 1 and in 6 (30%) with genotype non-1 (P = 0.906). There was a significant difference in fibrosis stage between groups (P = 0.005). In group I (N = 30), one patient had stage F0/F1 of fibrosis, while in group II (N = 65), 22 (33.8%) patients had minimal or no fibrosis. Fibrosis stage F2/F3 was observed in 70% of group I patients compared to 46.2% of group II. Eighty-five patients were treated with a combination of interferon and ribavirin; 29 of them (34.1%) had a sustained virologic response and 8 (27.6%) of them had hepatic iron overload. Iron overload was detected in 18 (32.1%) of the 56 non-responders (P = 0.73). Hepatic iron overload was frequent among patients with chronic hepatitis C and was associated with a more severe stage of liver fibrosis. There was no association between iron overload and HCV genotype and response to interferon and ribavirin therapy.

Mechanisms underlying gas exchange alterations in an experimental model of pulmonary embolism

The aim of the present study was to determine the ventilation/perfusion ratio that contributes to hypoxemia in pulmonary embolism by analyzing blood gases and volumetric capnography in a model of experimental acute pulmonary embolism. Pulmonary embolization with autologous blood clots was induced in seven pigs weighing 24.00 ± 0.6 kg, anesthetized and mechanically ventilated. Significant changes occurred from baseline to 20 min after embolization, such as reduction in oxygen partial pressures in arterial blood (from 87.71 ± 8.64 to 39.14 ± 6.77 mmHg) and alveolar air (from 92.97 ± 2.14 to 63.91 ± 8.27 mmHg). The effective alveolar ventilation exhibited a significant reduction (from 199.62 ± 42.01 to 84.34 ± 44.13) consistent with the fall in alveolar gas volume that effectively participated in gas exchange. The relation between the alveolar ventilation that effectively participated in gas exchange and cardiac output (V Aeff/Q ratio) also presented a significant reduction after embolization (from 0.96 ± 0.34 to 0.33 ± 0.17 fraction). The carbon dioxide partial pressure increased significantly in arterial blood (from 37.51 ± 1.71 to 60.76 ± 6.62 mmHg), but decreased significantly in exhaled air at the end of the respiratory cycle (from 35.57 ± 1.22 to 23.15 ± 8.24 mmHg). Exhaled air at the end of the respiratory cycle returned to baseline values 40 min after embolism. The arterial to alveolar carbon dioxide gradient increased significantly (from 1.94 ± 1.36 to 37.61 ± 12.79 mmHg), as also did the calculated alveolar (from 56.38 ± 22.47 to 178.09 ± 37.46 mL) and physiological (from 0.37 ± 0.05 to 0.75 ± 0.10 fraction) dead spaces. Based on our data, we conclude that the severe arterial hypoxemia observed in this experimental model may be attributed to the reduction of the V Aeff/Q ratio. We were also able to demonstrate that V Aeff/Q progressively improves after embolization, a fact attributed to the alveolar ventilation redistribution induced by hypocapnic bronchoconstriction.

Cardiac and pulmonary alterations in symptomatic and asymptomatic dogs infectednaturally with Leishmania (Leishmania) chagasi

Fifteen symptomatic and seven asymptomatic dogs infected naturally with Leishmania chagasi were examined in order to identify the presence of parasites and changes in heart and lung. Histopathological, cytological, and immunohistochemical analyses were performed on samples of heart and lung tissues. An inflammatory reaction characterized by inflammatory mononuclear, perivascular and intermuscular infiltrates was observed in both symptomatic and asymptomatic animals on histopathological analysis of the heart. In the lung, there was thickening of the alveolar septa due to congestion, edema, inflammatory infiltrate, and fibroblast proliferation. A focal reaction was observed although a diffuse reaction was present in both groups. On cytological examination, heart and lung imprints revealed amastigotes in two symptomatic animals and heart imprints were found in 1 asymptomatic dog. Immunoperoxidase staining showed amastigotes in the lung and heart of only 1 of 6 symptomatic animals examined. Within the ethical principles and limits of this research, it can be inferred that the study of heart and lung alterations in canine visceral leishmaniasis is increasingly important for understanding the problem related to humans. Dogs with visceral leishmaniasis were a good experimental model, since infection was caused by the same agent and the animals developed clinical, pathological and immunological alterations similar to those observed in humans.

Genomic alterations detected by comparative genomic hybridization in ovarian endometriomas

Endometriosis is a complex and multifactorial disease. Chromosomal imbalance screening in endometriotic tissue can be used to detect hot-spot regions in the search for a possible genetic marker for endometriosis. The objective of the present study was to detect chromosomal imbalances by comparative genomic hybridization (CGH) in ectopic tissue samples from ovarian endometriomas and eutopic tissue from the same patients. We evaluated 10 ovarian endometriotic tissues and 10 eutopic endometrial tissues by metaphase CGH. CGH was prepared with normal and test DNA enzymatically digested, ligated to adaptors and amplified by PCR. A second PCR was performed for DNA labeling. Equal amounts of both normal and test-labeled DNA were hybridized in human normal metaphases. The Isis FISH Imaging System V 5.0 software was used for chromosome analysis. In both eutopic and ectopic groups, 4/10 samples presented chromosomal alterations, mainly chromosomal gains. CGH identified 11q12.3-q13.1, 17p11.1-p12, 17q25.3-qter, and 19p as critical regions. Genomic imbalances in 11q, 17p, 17q, and 19p were detected in normal eutopic and/or ectopic endometrium from women with ovarian endometriosis. These regions contain genes such as POLR2G, MXRA7 and UBA52 involved in biological processes that may lead to the establishment and maintenance of endometriotic implants. This genomic imbalance may affect genes in which dysregulation impacts both eutopic and ectopic endometrium.

Plasma concentrations and placental immunostaining of interleukin-10 and tumornecrosis factor-α as predictors of alterations in the embryo-fetal organism and the placental development of diabetic rats

Interleukin-10 (IL-10) appears to be the key cytokine for the maintenance of pregnancy and inhibits the secretion of inflammatory cytokines such as tumor necrosis factor-α (TNF-α). However, there are no studies evaluating the profile of these cytokines in diabetic rat models. Thus, our aim was to analyze IL-10 and TNF-α immunostaining in placental tissue and their respective concentrations in maternal plasma during pregnancy in diabetic rats in order to determine whether these cytokines can be used as predictors of alterations in the embryo-fetal organism and in placental development. These parameters were evaluated in non-diabetic (control; N = 15) and Wistar rats with streptozotocin (STZ)-induced diabetes (N = 15). At term, the dams (100 days of life) were killed under anesthesia and plasma and placental samples were collected for IL-10 and TNF-α determinations by ELISA and immunohistochemistry, respectively. The reproductive performance was analyzed. Plasma IL-10 concentrations were reduced in STZ rats compared to controls (7.6 ± 4.5 vs 20.9 ± 8.1 pg/mL). The placental scores of immunostaining intensity did not differ between groups (P > 0.05). Prevalence analysis showed that the IL-10 expression followed TNF-α expression, showing a balance between them. STZ rats also presented impaired reproductive performance and reduced plasma IL-10 levels related to damage during early embryonic development. However, the increased placental IL-10 as a compensatory mechanism for the deficit of maternal regulation permitted embryo development. Therefore, the data suggest that IL-10 can be used as a predictor of changes in the embryo-fetal organism and in placental development in pregnant diabetic rats.

Epilepsy-induced electrocardiographic alterations following cardiac ischemia and reperfusion in rats

The present study evaluated electrocardiographic alterations in rats with epilepsy submitted to an acute myocardial infarction (AMI) model induced by cardiac ischemia and reperfusion. Rats were randomly divided into two groups: control (n=12) and epilepsy (n=14). It was found that rats with epilepsy presented a significant reduction in atrioventricular block incidence following the ischemia and reperfusion procedure. In addition, significant alterations were observed in electrocardiogram intervals during the stabilization, ischemia, and reperfusion periods of rats with epilepsy compared to control rats. It was noted that rats with epilepsy presented a significant increase in the QRS interval during the stabilization period in relation to control rats (P<0.01). During the ischemia period, there was an increase in the QRS interval (P<0.05) and a reduction in the P wave and QT intervals (P<0.05 for both) in rats with epilepsy compared to control rats. During the reperfusion period, a significant reduction in the QT interval (P<0.01) was verified in the epilepsy group in relation to the control group. Our results indicate that rats submitted to an epilepsy model induced by pilocarpine presented electrical conductivity alterations of cardiac tissue, mainly during an AMI episode.

Specific alterations in plasma proteins during depressed, manic, and euthymic states of bipolar disorder

Bipolar disorder (BD) is a common psychiatric mood disorder affecting more than 1-2% of the general population of different European countries. Unfortunately, there is no objective laboratory-based test to aid BD diagnosis or monitor its progression, and little is known about the molecular basis of BD. Here, we performed a comparative proteomic study to identify differentially expressed plasma proteins in various BD mood states (depressed BD, manic BD, and euthymic BD) relative to healthy controls. A total of 10 euthymic BD, 20 depressed BD, 15 manic BD, and 20 demographically matched healthy control subjects were recruited. Seven high-abundance proteins were immunodepleted in plasma samples from the 4 experimental groups, which were then subjected to proteome-wide expression profiling by two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight tandem mass spectrometry. Proteomic results were validated by immunoblotting and bioinformatically analyzed using MetaCore. From a total of 32 proteins identified with 1.5-fold changes in expression compared with healthy controls, 16 proteins were perturbed in BD independent of mood state, while 16 proteins were specifically associated with particular BD mood states. Two mood-independent differential proteins, apolipoprotein (Apo) A1 and Apo L1, suggest that BD pathophysiology may be associated with early perturbations in lipid metabolism. Moreover, down-regulation of one mood-dependent protein, carbonic anhydrase 1 (CA-1), suggests it may be involved in the pathophysiology of depressive episodes in BD. Thus, BD pathophysiology may be associated with early perturbations in lipid metabolism that are independent of mood state, while CA-1 may be involved in the pathophysiology of depressive episodes.

Effects of grilling on cholesterol oxide formation and fatty acids alterations in fish

Due to the adverse effects of the cholesterol oxidation products for the human health, the search of the occurrence and the quantification of these compounds in foods are considered of great importance. In this paper the effect of grilling in hake and sardine on cholesterol oxides formation and fatty acids alterations was investigated. The main fatty acids determined in both fishes were docosahexaenoic (DHA), oleic, eicosapentaenoic (EPA) and palmitoleic. The total lipids, fatty acids and cholesterol contents were decreased significantly (p < 0.02) after thermal treatment, with simultaneous increase of the cholesterol oxides contents. The cholesterol oxides determined in both species in the present study were: 19-hydroxycholesterol, 24(S)-hydroxycholesterol, 22(S) hydroxycholesterol, 25-hydroxycholesterol, 25(R)-hydroxycholesterol and 7-ketocolesterol. Besides the presence of the cholesterol oxides in raw fishes, there were a greater number of products resulting from the oxidation of cholesterol side chain, a fact rarely observed in foods.

Influence of packaging and potassium sorbate on the physical, physicochemical and microbiological alterations of guava preserves

The elaboration of preserves through fruit processing is a promising alternative for their conservation. Such processing provides pleasant flavor due to the increase of sweetness and allows good conservation of the product for a prolonged time. Seeking quality and higher durability of fruit preserves, the purpose of this work was to evaluate the interference of potassium sorbate addition, and polypropylene, metallic and cellophane film packaging on the quality of guava (Psidium guajava L.) preserves during storage, through the physical, physiochemical and microbiological characteristics. The physical, physiochemical and microbiological analyses showed that the different types of packaging did not interfere in the stability of the guava preserves until the 5th month of storage - time being the factor that most influences the quality of the preserves when stored under temperature and humidity of 19.6 °C and 76.2%, respectively. The potassium sorbate caused an increase of the soluble solid levels and a decrease of the water activity. Regardless of the treatment, the preserves remained microbiologically stable during storage.

Alterations of palm oil (Elaeis guineensis) in the continuous industrial par frying of breaded chicken snacks

The physical and chemical alterations in palm oil during continuous industrial par frying of breaded chicken snacks were evaluated using a pseudo first-order kinetic model. The acidity index, refractive index, concentration of polar compounds, viscosity, color, and absorbance (232 and 268 nm) of 238 samples of the frying oil collected during 26 days of production were analyzed. For all of the analyses, the results of the oil were below the limits recommended for oil disposal, indicating that the processing conditions were safe and that under these experimental conditions the oil remained suitable for frying. The linear regressions were significant for refractive index, content of polar compounds, and lightness (L*). The content of polar compounds was determined using a cooking oil tester, and it had the best fit to the proposed model and can be used as an effective index for monitoring palm oil during the continuous par frying of breaded chicken snacks. The high turnover rate of the oil was important for maintaining the oil in good running conditions.