Spatial learning ability of rats following differing levels of exposure to alcohol during early postnatal life

Rats exposed to a relatively high dose (7.5 g/kg body weight) of alcohol on either the fifth or tenth postnatal day of age have been reported to have long-lasting deficits in spatial learning ability as tested on the Morris water maze task. The question arises concerning the level of alcohol required to achieve this effect. Wistar rats were exposed to either 2, 4 or 6 g/kg body weight of ethanol administered as a 10% solution. This ethanol was given over an 8-h period on the fifth postnatal day of age by means of an intragastric cannula. Gastrostomy controls received a 5% sucrose solution substituted isocalorically for the ethanol. Another set of pups raised by their mother were used as suckle controls. All surgical procedures were carried out under halothane vapour anaesthesia. After the artificial feeding regimes all pups were returned to lactating dams and weaned at 21 days of age. The spatial learning ability of these rats was tested in the Morris water maze when they were between 61-64 days of age. This task requires the rats to swim in a pool containing water made opaque and locate and climb onto a submerged platform. The time taken to accomplish this is known as the escape latency. Each rat was subjected to 24 trials over 3 days of the test period. Statistical analysis of the escape latency data revealed that the rats given 6 g/kg body weight of ethanol had significant deficits in their spatial learning ability compared with their control groups. However, there was no significant difference in spatial learning ability for the rats given either 2 or 4 g/kg body weight of ethanol compared with their respective gastrostomy or suckle control animals. We concluded that ethanol exposure greater than 4 g/kg over an 8-h period to 5-day-old rats is required for them to develop long-term deficits in spatial learning behaviour. (C) 1998 Elsevier Science Inc.

Action of aromatase inhibitor for treatment of uterine leiomyoma in perimenopausal patients

Objective: To assess the effect of the aromatase inhibitor on patients with leiomyoma in the reproductive stage regarding reduction of uterine volume and control of symptoms. Design: Clinical study. Setting: Academic clinical practice. Patient(s): Twenty patients, over 35 years of age, with symptomatic uterine leiomyoma. Intervention(s): Anastrozol, 1 mg/day for 12 weeks. Main Outcome Measure(s): Measurement of uterine volume, assessment of symptoms related to uterine leiomyoma, serum assay of follicle stimulating hormone (FSH), and estradiol. Results: Average reduction of uterine volume of 9.32%, attaining up to 32%, and reduction of symptoms of uterine leiomyoma (menstrual volume, duration of menstruation, and dysmenorrhea). No significant change in serum levels of FSH and estradiol during use of the medication were observed. Conclusion(S): Anastrozol proved to be effective in reducing the volume of the uterus-leiomyoma structure, leading to the control of symptoms connected with the disorder without changes in serum FSH and estradiol. (Fertil Steril (R) 2009;91:240-3. (c) 2009 by American Society for Reproductive Medicine.)

Maternal alcohol consumption may influence cord blood ascorbic acid concentration: findings from a study of Brazilian mothers and their newborns

Studies that have investigated ascorbic acid (AA) concentrations in cord blood have pointed to significant associations with maternal blood AA concentrations. smoking, age, diet, type of delivery, duration of gestation, fetal distress and birth weight. The aim of the present study was to determine the relationship between cord blood AA concentrations in newborns and maternal characteristics. A total of 117 Brazilian healthy parturients were included in this cross-sectional study. The concentrations of AA in blood were determined by the HPLC method. Data concerning socio-economic, demographic, obstetric, nutritional and health characteristics of the parturients, including alcohol consumption and smoking habit, were assessed by a standardised questionnaire. A FFQ was used to investigate the intake of foods rich in vitamin C. Cord blood AA concentration was significantly correlated with per capita income (r 0.26; P=0.005), maternal blood AA concentration (r 0.48; P<0.001) and maternal vitamin C-rich food intake score (r 0.36; P<0.001). The linear regression model including maternal AA concentration, alcohol consumption, smoking, parity, vitamin C-rich food intake score and per capita income explained 31.13% of the variation in cord blood AA concentrations in newborns. We recommend further experimental studies to assess the effects of ethanol on placental AA uptake, and epidemiological cohort studies to evaluate in detail the influence of maternal alcohol consumption on cord blood AA concentrations.

Assessment of a New Experimental Model of Isolated Right Ventricular Failure

We assessed a new experimental model of isolated right ventricular (RV) failure, achieved by means of intramyocardial injection of ethanol. RV dysfunction was induced in 13 mongrel dogs via multiple injections of 96% ethanol (total dose 1 mL/kg), all over the inlet and trabecular RV free walls. Hemodynamic and metabolic parameters were evaluated at baseline, after ethanol injection, and on the 14th postoperative day (POD). Echocardiographic parameters were evaluated at baseline, on the sixth POD, and on the 13th POD. The animals were then euthanized for histopathological analysis of the hearts. There was a 15.4% mortality rate. We noticed a decrease in pulmonary blood flow right after RV failure (P = 0.0018), as well as during reoperation on the 14th POD (P = 0.002). The induced RV dysfunction caused an increase in venous lactate levels immediately after ethanol injection and on the 14th POD (P < 0.0003). The echocardiogram revealed a decrease in the RV ejection fraction on the sixth and 13th PODs (P = 0.0001). There was an increased RV end-diastolic volume on the sixth (P = 0.0001) and 13th PODs (P = 0.0084). The right ventricle showed a 74% +/- 0.06% transmural infarction area, with necrotic lesions aged 14 days. Intramyocardial ethanol injection has allowed the creation of a reproducible and inexpensive model of RV failure. The hemodynamic, metabolic, and echocardiographic parameters assessed at different protocol times are compatible with severe RV failure. This model may be useful in understanding the pathophysiology of isolated right-sided heart failure, as well as in the assessment of ventricular assist devices.

Pregnancy outcome in ethanol-treated mice with folic acid supplementation in saccharose

Introduction Maternal folic acid deficiency is the most important metabolic factor in the etiology of neural tube defects (NTD) and is reduced by ethanol, which is extensively consumed by young women. Objective The objective of the study was to determine whether folic acid supplementation in dietary saccharose is efficient in the prevention NTD induced by ethanol in fetuses of Swiss mice. Materials and methods Pregnant mice were divided into four groups of six animals each: control (C), ethanol (E), deficient-supplemented (DS), and deficient-supplemented+ethanol (DSE). Groups C and E received commercial mouse chow (containing 3 mg/kg folic acid) throughout the experiment, while groups DS and DSE received a folic acid-free diet with the addition of saccharose supplemented with folic acid (2 mg/kg folic acid) in water. Group E and DSE animals received ethanol (4 g/kg) administered intraperitoneally from the seventh to the ninth gestational day (gd) and were euthanized on the 18th gd, while groups C and DS received saline. Results Congenital anomalies were observed in groups E and DSE. The fetal weight and length of the animals in group E were lower than in groups C and DS and, in group DSE, were lower than in groups C and DS. The placental diameter of group E was smaller than that of group C, and the placental weight of group C animals was lower than that of groups E, DSE, and DS. Conclusion The study demonstrated that dietary supplementation with folate in saccharose is an accessible means of consumption that could be further diffused but in an increased dose than recommended to reduce the teratogenic effects of ethanol.

Antioxidant Effect of Thiamine on Acutely Alcoholized Rats and Lack of Efficacy Using Thiamine or Glucose to Reduce Blood Alcohol Content

Although there is no consensus about the use of glucose and thiamine for the treatment of acute ethanol intoxication, this is a routine practice in many countries. Our objective was to determine the efficacy of this treatment and the changes it causes in the antioxidant status of the liver. Male Wistar rats were intoxicated with an ethanol dose of 5 g/kg and divided into three groups: ethanol (EtOH; untreated), EtOH+G (treated with glucose), and EtOH+B1 (treated with thiamine). Blood and urinary ethanol as well as hepatic malondialdehyde, reduced glutathione and vitamin E were determined in all animals. Blood alcohol levels did not differ between groups, although urinary excretion was about four times higher in the group treated with thiamine (EtOH+B1). The malondialdehyde, reduced glutathione and vitamin E values used here as parameters of the antioxidant system of the liver showed improvement for the thiamine-treated group (EtOH+B1). Treatment with glucose or thiamine was ineffective in reducing blood alcohol levels in rats with acute ethanol intoxication. However, the beneficial effect of thiamine as an antioxidant for ethanol metabolism was demonstrated. Further investigations are necessary to clarify the urinary excretion of ethanol reported here for the first time and the possibility of using thiamine as an antioxidant in situations of chronic alcohol use.

Increased circulating vasopressin may account for ethanol-induced hypertension in rats

BACKGROUND Long-term ethanol intake has been reported to evoke both hypertension and increase of systemic vasopressin levels in rats. METHODS In this work, we investigated the involvement of systemic vasopressin in the hypertension evoked in rats by long-term ethanol (20% vol/vol) intake for 2 weeks, by systemic treatment with the VI-vasopressin receptor antagonist dTyr(CH2)5(Me)AVP (50 mu g/kg). Moreover, plasma arginine-vasopressin (AVP) content was quantified using an AVP radioimmunoassay and the expression of vasopressin mRNA in the supraoptic (SON) and paraventricular (PVN) nuclei was measured using real-time PCR. RESULTS Mild hypertension was observed after 2 weeks of ethanol treatment when compared with control animals. Moreover, an increase in both the expression of vasopressin mRNA and the vasopressin blood content was observed in ethanol-treated rats in comparison to the OF control group. Basal blood pressure levels of ethanol-treated animals were significantly reduced by IV treatment with the V1-vasopressin receptor antagonist dTyr(CH2)5(Me)AVR However, dTyr(CH2)5(Me) AVP had no effect on the blood pressure of control animals. CONCLUSIONS The results indicate that mild hypertension is already observed at an early phase of ethanol consumption in rats. Because the content of circulating vasopressin was increased in ethanol-treated rats and their basal blood pressure returned to control levels after IV treatment with a VI-vasopressin receptor antagonist, it is proposed that increased circulating vasopressin content may mediate the hypertension observed in ethanol-treated rats.

Role of cytokines (TNF-alpha, IL-1 beta and KC) in the pathogenesis of CPT-11-induced intestinal mucositis in mice: effect of pentoxifylline and thalidomide

Introduction Irinotecan (CPT-11) is an inhibitor of DNA topoisomerase I and is clinically effective against several cancers. A major toxic effect of CPT-11 is delayed diarrhea; however, the exact mechanism by which the drug induces diarrhea has not been established. Purpose Elucidate the mechanisms of induction of delayed diarrhea and determine the effects of the cytokine production inhibitor pentoxifylline (PTX) and thalidomide (TLD) in the experimental model of intestinal mucositis, induced by CPT-11. Materials and methods Intestinal mucositis was induced in male Swiss mice by intraperitoneal administration of CPT-11 (75 mg/kg) daily for 4 days. Animals received subcutaneous PTX (1.7, 5 and 15 mg/kg) or TLD (15, 30, 60 mg/kg) or 0.5 ml of saline daily for 5 and 7 days, starting 1 day before the first CPT-11 injection. The incidence of delayed diarrhea was monitored by scores and the animals were sacrificed on the 5th and 7th experimental day for histological analysis, immunohistochemistry for TNF-alpha and assay of myeloperoxidase (MPO) activity, tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and KC ELISA. Results CPT-11 caused significant diarrhea, histopathological alterations (inflammatory cell infiltration, loss of crypt architecture and villus shortening) and increased intestinal tissue MPO activity, TNF-alpha, IL-1 beta and KC level and TNF-alpha immuno-staining. PTX inhibited delayed diarrhea of mice submitted to intestinal mucositis and reduced histopathological damage, intestinal MPO activity, tissue level of TNF-alpha, IL-1 beta and KC and TNF-alpha immuno-staining. TLD significantly reduced the lesions induced by CPT-11 in intestinal mucosa, decreased MPO activity, TNF-alpha tissue level and TNF-alpha immuno-staining, but did not reduce the severity of diarrhea. Conclusion These results suggest an important role of TNF-alpha, IL-1 beta and KC in the pathogenesis of intestinal mucositis induced by CPT-11.

Vitamin E and tannic acid improve DNA damage in rats submitted chronic ethanol administration

Purpose - Chronic ethanol consumption induces lipid peroxidation by increasing free radicals or reducing antioxidants and may increase damage to hepatic DNA. Tannins are polyphenolic metabolites present in various plants and one of their effects is antioxidant activity that reduces lipoperoxidation, as is the case for vitamin E. This paper aims to assess the role of tannic acid and vitamin E in lipid peroxidation and in DNA damage in rats receiving ethanol. Design/methodology/approach - A total of 60 Wistar rats were divided into six groups: control + ethanol (0-24hs), tannic acid + ethanol (0-24 hs), and vitamin E + ethanol (0-24 hs). The animals were sacrificed immediately (0 hour) or 24 hours after a period of four weeks of ethanol administration and the following measurements were made: plasma vitamin E and liver glutathione, thiobarbituric acid resistant substances, and a-tocopherol. The comet test was also applied to hepatocytes. Findings - Ethanol administration led to an increase in DNA damage (148.67 +/- 15.45 versus 172.63 +/- 18.94) during a period of 24 hours which was not detected in the groups receiving tannic acid or vitamin E. Steatosis was lower in the groups receiving tannic acid. Originality/value - The paper highlights that antioxidant role of vitamin E and of tannic acid in biological systems submitted to oxidative stress should be reevaluated, especially regarding the protective role of tannic acid against hepatic steatosis.

Chronic Ethanol Consumption Induces Cavernosal Smooth Muscle Dysfunction in Rats

OBJECTIVES To investigate the effects of chronic ethanol consumption on nitric oxide (NO)-mediated relaxation in rat cavernosal smooth muscle (CSM). METHODS Male wistar rats were divided into 2 groups: control and ethanol. CSM obtained from both groups were mounted in organ chambers for measurement of isometric tension. Contraction of the strips was induced by electrical field stimulation (EFS, 1-32 Hertz) and phenylephrine. We also evaluated the effect of ethanol consumption on the relaxation induced by acetylcholine (0.01-1000 mu mol L(-1)), sodium nitroprusside (SNP, 0.01-1000 mu mol L(-1)), or EFS (1-32 Hz) in strips precontracted with phenylephrine (10 mu mol L(-1)). Blood ethanol, serum testosterone levels, and basal nitrate generation were determined. Immunoexpression of endothelial NO synthase (eNOS) and inducible NO synthase (iNOS) was also accessed. RESULTS Ethanol intake for 4 weeks significantly increased noradrenergic nerve-mediated contractions of CSM in response to EFS. The endothelium-dependent relaxation induced by acetylcholine decreased after the ethanol treatment. Ethanol consumption decreased serum testosterone levels but did not affect the nitrate levels on rat CSM. The mRNA and protein levels for eNOS and iNOS receptors were increased in CSM from ethanol-treated rats. CONCLUSIONS Ethanol consumption reduces endothelium-dependent relaxation induced by acetylcholine, but does not affect SNP or EFS-induced relaxation, suggesting that ethanol disrupts the endothelial function. Despite the overexpression of eNOS and iNOS in ethanol-treated rats, the impaired relaxation induced by acetylcholine may suggest that chronic ethanol consumption induces endothelial dysfunction. UROLOGY 74: 1250-1256, 2009. (C) 2009 Published by Elsevier Inc.

Process mineralogy of fluorosilicate minerals in OK Tedi ores

The impact of fluorine in copper flotation was relatively unknown until the introduction of skarn ores in the Ok Tedi concentrator. Fluorine in the copper concentrates reports to the gas phase during the smelting stage and forms a corrosive H2SO4-HCl-HF acid brine mixture which must be neutralised. This work was aimed at studying the mineralogy of the fluorosilicate minerals contained in the various oretypes present in the Ok Tedi porphyry copper deposit. The electron microprobe was used to analyse for fluorine and hence identify the fluorosilicate minerals in each oretype. This study revealed talc, phlogopite, biotite, clays, amphiboles, fluoroapatite and titanite to be the sources of fluorine in the orebody. Laboratory and plant investigations were conducted to study the flotation response of these minerals. Chemical assaying of the products of these tests was done to determine the bulk assay of fluorine, Using Rietveld analysis, quantitative estimates of the fluorosilicate minerals in these products were generated. Marrying of the bulk assay with the respective mineralogical assay enabled the understanding of the flotation behavior of fluorine and it's associated mineralogy. Talc and phlogopite were found to be the causes of the fluorine problem at Ok Tedi. (C) 2001 Elsevier Science Ltd. All rights reserved.

Elucidation of reaction scheme describing malondialdehyde-acetaldehyde-protein adduct formation

Malondialdehyde and acetaldehyde react together with proteins and form hybrid protein conjugates designated as MAA adducts, which have been detected in livers of ethanol-fed animals. Our previous studies have shown that MAA adducts are comprised of two distinct products. One adduct is composed of two molecules of malondialdehyde and one molecule of acetaldehyde and was identified as the 4-methpl-1,4-dihydropyridine-3,5-dicarbaldehyde derivative of an amino group (MHHDC adduct). The other adduct is a 1:1 adduct of malondialdehyde and acetaldehyde and was identified as the 2-formyl-3-(alkylamino)butanal derivative of an amino group (FAAB adduct). In this study, information on the mechanism of MAA adduct formation was obtained, focusing on whether the FAAB adduct serves as a precursor for the MDHDC adduct. Upon the basis of chemical analysis and NMR spectroscopy, two initial reaction steps appear to be a prerequisite for MDHDC formation. One step involves the reaction of one molecule of malondialdehyde and one of acetaldehyde with an amino group of a protein to form the FAAB product, while the other step involves the generation of a malondialdehyde-enamine. It appears that generation of the MDHDC adduct requires the FAAB moiety to be transferred to the nitrogen of the MDA-enamine. For efficient reaction of FAAB with the enamine to take place, additional experiments indicated that these two intermediates likely must be in positions on the protein of close proximity to each other. Further studies showed that the incubation of liver proteins from ethanol-fed rats with MDA resulted in a marked generation of MDHDC adducts, indicating the presence of a pool of FAAB adducts in the liver of ethanol-fed animals. Overall, these findings show that MDHDC-protein adduct formation occurs via the reaction of the FAAB moiety with a malondialdehyde-enamine, and further suggest that a similar mechanism may be operative in vivo in the liver during prolonged ethanol consumption.

A sensitive and specific assay for glutathione with potential application to glutathione disulphide, using high-performance liquid chromatography-tandem mass spectrometry

We have utilised the combination of sensitivity and specificity afforded by coupling high-performance liquid chromatography (HPLC) to a tandem mass spectrometer (MS-MS) to produce an assay which is suitable for assaying glutathione (GSH) concentrations in liver tissue. The sensitivity suggests it may also be suitable for extrahepatic tissues, The method has been validated for GSH using mouse liver samples and also allows the assay of GSSG. The stability of GSH under conditions relevant to the assay has been determined. A 20-mul amount of a diluted methanol extract of tissue is injected with detection limits of 0.2 pmol for GSH and 2 pmol for GSSG. The HPLC uses an Altima C-18 (150X4.6 mm, 5 mum) column at 35 degreesC. Chromatography utilises a linear gradient from 0 to 10% methanol in 0.1% formic acid over 5 min, with a final isocratic stage holding at 10% methanol for 5 min. Total flow rate is 0.8 ml/min. The transition from the M+H ion (308.1 m/z for GSH, and 613.3 m/z for GSSG) to the 162.0 m/z (GSH) and 355.3 m/z (GSSG) fragments are monitored. (C) 2001 Elsevier Science B.V. All rights reserved.

Calorimetric demonstration of the potential of molecular crowding to emulate the effect of an allosteric activator on pyruvate kinase kinetics

A method based on isothermal calorimetry is described for the direct kinetic assay of pyruvate kinase. In agreement with earlier findings based on the standard coupled assay system for this enzyme in the presence of a fixed ADP concentration, the essentially rectangular hyperbolic dependence of initial velocity upon phosphoenolpyruvate concentration is rendered sigmoidal by the allosteric inhibitor phenylalanine. This effect of phenylalanine can be countered by including a high concentration of a space- filling osmolyte such as proline in the reaction mixtures. This investigation thus affords a dramatic example that illustrates the need to consider potential consequences of thermodynamic nonideality on the kinetics of enzyme reactions in crowded molecular environments such as the cell cytoplasm.

Characterization of micro-mesoporous carbonaceous materials. Calculations of adsorption isotherm of hydrocarbons

In this paper we apply a method recently developed by Do and co-workers(1) for the prediction of adsorption isotherms of pure vapors on carbonaceous materials. The information required for the prediction is the pore size distribution and the BET constant, C, of a corresponding nonporous surface (graphite). The dispersive adsorption force is assumed to be the dominant force in adsorption mechanism. This applies to nonpolar and weakly polar hydrocarbons. We test this predictive model against the adsorption data of benzene, toluene, n-pentane, n-hexane, and ethanol on a commercial activated carbon. It is found that the predictions are excellent for all adsorbates tested with the exception of ethanol where the predicted values are about 10% less than the experimental data, and this is probably attributed to the electrostatic interaction between ethanol molecules and the functional groups on the carbon surfaces.