Brain alterations in GABA, glutamate and glutamine markers after chronic atrazine exposure in the male albino rat.

Atrazine (ATR; 2-chloro-4-ethylamino-6-isopropylamino-s-triazine) is an herbicide widely used to kill annual grasses and broadleaf weeds in crops such as corn, sorghum, and sugarcane. Studies in rodents have shown that chronic ATR exposure is associated with alterations in the nigrostriatal dopaminergic pathway such as hyperactivity, decreased striatal dopamine levels, and diminished numbers of tyrosine hydroxylase positive cells in substantia nigra pars compacta. However, the effects of ATR on neurotransmitters such as GABA and glutamate have been scarcely studied. To evaluate the impact of ATR on motor and anxiety tasks, tissue levels of GABA, glutamate, glutamine, and extracellular and potassium-evoked release of glutamate in the striatum, we daily exposed Sprague-Dawley male rats to 1 or 10 mg ATR/kg of body weight for 12-14 months. As previously reported, chronic ATR exposure causes hyperactivity in the group exposed to 10 mg ATR/kg and increased anxiety in both groups exposed to ATR. GABA, glutamate, and glutamine levels were differentially altered in brain regions related to nigrostriatal and mesolimbic systems, the amygdala, and the prefrontal cortex. The groups exposed to 10 mg ATR/kg showed increased extracellular levels and release of glutamate in the striatum. These neurochemical alterations could underlie the behavioral changes observed in rats. These results indicate that chronic exposure to the herbicide ATR disrupts the neurochemistry of several brain structures and could be a risk factor for the development of neurodegenerative diseases.

Transient chaos under coordinate transformations in relativistic systems.

We use the Hénon-Heiles system as a paradigmatic model for chaotic scattering to study the Lorentz factor effects on its transient chaotic dynamics. In particular, we focus on how time dilation occurs within the scattering region by measuring the time with a clock attached to the particle. We observe that the several events of time dilation that the particle undergoes exhibit sensitivity to the initial conditions. However, the structure of the singularities appearing in the escape time function remains invariant under coordinate transformations. This occurs because the singularities are closely related to the chaotic saddle. We then demonstrate using a Cantor-like set approach that the fractal dimension of the escape time function is relativistic invariant. In order to verify this result, we compute by means of the uncertainty dimension algorithm the fractal dimensions of the escape time functions as measured with an inertial frame and a frame comoving with the particle. We conclude that, from a mathematical point of view, chaotic transient phenomena are equally predictable in any reference frame and that transient chaos is coordinate invariant.

The effect of aromatherapy with lavender (Lavandula angustifolia) on serum melatonin levels.

OBJECTIVE: Physiologically, blood melatonin levels decrease as a person ages and the older adult commonly presents with insomnia and other types of sleep disorders. Alternative therapies can be used to attenuate sleep disturbances. The aim of the present study was to analyze the effect of aromatherapy with lavender on serum melatonin levels in the noninstitutionalized older adult (OA). DESIGN AND SETTING: A pre-experimental, quantitative study with a pre-test - post-test design was conducted on 67 OAs that included both sexes. MAIN OUTCOME MEASURES: Serum melatonin levels were measured before and after eight sessions of aromatherapy with lavender that lasted 4 weeks. The results were expressed as mean ±â€¯standard deviation of melatonin levels (pg/ml). The differences were compared using the Student's t-test and statistical significance was set at a p ≤ 0.05. RESULTS: Blood melatonin levels significantly increased in the total population after the intervention with aromatherapy (pg/ml): 102.3 ±â€¯33.4 VS 132.5 ±â€¯42.3, p = 0.000004. There were significant differences in the pre-test and post-test phases in the women and men measured as separate groups (p = 0.00005 and p = 0.026), respectively. However, those differences were not observed when the measurements were compared between the two sexes, before (p = 0.64) or after (p = 0.31) the intervention. CONCLUSION: Aromatherapy with lavender essential oil similarly favors an increase in blood melatonin levels in both older adult men and women.

Inhibitory effect of cyclic terpenes (limonene, menthol, menthone and thymol) on Fusarium verticillioides MRC 826 growth and fumonisin B1 biosynthesis.

The minimum inhibitory concentration (MIC) of cyclic terpenes (limonene, menthol, menthone and thymol) against Fusarium verticillioides MRC 826 was assessed by using the semisolid agar antifungal susceptibility (SAAS) technique. Limonene, menthol, menthone and thymol were evaluated at final concentrations of 25, 50, 75, 150, 200, 250, 500 and 1000 microL/L of culture medium. Limonene and thymol showed the highest inhibitory effects on F. verticillioides development. Thus, the effects of monoterpenes on fumonisin B1 (FB1) biosynthesis were evaluated by using corn grain (Zea mays) as substrate. The monoterpenes were inserted on maize 1 day before inoculation with a conidial suspension of F. verticillioides to give final concentrations of 75 ppm. At this concentration, thymol was the most active inhibitor on FB1 biosynthesis.

Subchronic mycotoxicoses in rats. Histopathological changes and modulation of the sphinganine to sphingosine (Sa/So) ratio imbalance induced by Fusarium verticillioides culture material, due to the coexistence of aflatoxin B1 in the diet.

Mycotoxicoses are diseases caused by consumption of diets contaminated with mycotoxins, a special class of fungal secondary metabolites. Fumonisin B1 (FB1) and aflatoxin B1 (AFB1), the main toxins synthesized by toxicogenic stocks of Fusarium spp. and Aspergillus spp., respectively, can coexist in grains and in its by-products. We investigated a probable synergism of a fumonisins-containing Fusarium verticillioides culture material and AFB1 in the induction of hepatocyte apoptosis in rats subchronically fed on a mixture of them. Furthermore, the possibility of modifications in the fumonisins-induced Sa/So ratio imbalance in tissues and urine from rats poisoned with this mycotoxin, due to the presence of AFB1 in the diet, was evaluated. The co-exposure to fumonisins and AFB1 produced a higher liver toxicity, with respect to their individual administration, inducing apoptosis and mitotic hepatocytes. There was an inversion of the typical Sa/So ratio in rats fed on the culture material as well as in those subjected to a diet co-contamined with fumonisins and AFB1. Moreover, the later had a synergistic effect in the induction of Sa/So variations in kidneys. Therefore, the mixture of fumonisins and AFB1 induced toxic responses which could not be considered a sum of the effects caused individually by these mycotoxins.

Comparison of coronary vasodilation with intravenous dipyridamole and adenosine.

Although both intravenous dipyridamole and adenosine have been used to produce coronary vasodilation during cardiac imaging, the relative potency of the commonly administered doses of these agents has not been evaluated. Accordingly, the coronary and systemic hemodynamic effects of intravenous adenosine (140 micrograms/kg per min) and intravenous dipyridamole (0.56 mg/kg over 4 min) were compared with a maximally dilating dose of intracoronary papaverine in 15 patients. Coronary blood flow responses were assessed using a Doppler catheter in a nonstenotic coronary artery. The protocol was discontinued in two patients because of transient asymptomatic atrioventricular (AV) block during adenosine infusion. The mean heart rate increased more with adenosine (11 +/- 9 beats/min) and dipyridamole (11 +/- 7 beats/min) than with papaverine (4 +/- 3 beats/min, p less than 0.05 vs. adenosine and papaverine). The mean arterial pressure decreased less with dipyridamole (-10 +/- 3 mm Hg) and papaverine (-9 +/- 4 mm Hg) than with adenosine (-16 +/- 5 mm Hg, p less than 0.01 vs. dipyridamole and papaverine). The peak/rest coronary blood flow velocity ratio was greater with papaverine (3.9 +/- 1.1) than with adenosine (3.4 +/- 1.2, p less than or equal to 0.05 vs. papaverine) or dipyridamole (3.1 +/- 1.2, p less than 0.01 vs. papaverine). A larger decrease in coronary resistance as measured by the coronary vascular resistance index occurred with papaverine (0.25 +/- 0.06) and adenosine (0.26 +/- 0.09) than with dipyridamole (0.31 +/- 0.10, p less than 0.01 vs. papaverine, p less than 0.05 vs. adenosine).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute effect of cigarette smoking on the coronary circulation: constriction of epicardial and resistance vessels.

OBJECTIVES: This study was performed to determine the acute effect of cigarette smoking on proximal and distal epicardial conduit and coronary resistance vessels. BACKGROUND: Cigarette smoking causes constriction of epicardial arteries and a decrease in coronary blood flow in patients with coronary artery disease, despite an increase in myocardial oxygen demand. The role of changes in resistance vessel tone in the acute coronary hemodynamic effect of smoking has not been examined. METHODS: Twenty-four long-term smokers were studied during cardiac catheterization after vasoactive medications had been discontinued. The effect of smoking one cigarette 10 to 15 mm long on proximal and distal conduit vessel segments was assessed before and immediately after smoking and at 5, 15 and 30 min after smoking (n = 8). To determine the effect of smoking on resistance vessels, coronary flow velocity was measured in a nonobstructed artery with a 3F intracoronary Doppler catheter before and for 5 min after smoking (n = 8). Eight patients were studied without smoking to control for spontaneous changes in conduit arterial diameter (n = 5) and resistance vessel tone (n = 3). RESULTS: The average diameter of proximal coronary artery segments decreased from 2.56 +/- 0.12 mm (mean +/- SEM) before smoking to 2.41 +/- 0.09 mm 5 min after smoking (-5 +/- 2%, p < 0.05). Distal coronary diameter decreased from 1.51 +/- 0.07 to 1.39 +/- 0.06 mm (-8 +/- 2%, p < 0.01). Marked focal vasoconstriction after smoking was observed in two patients. Coronary diameter returned to baseline by 30 min after smoking. There was no change in vessel diameter in control patients. Despite a significant increase in the heart rate-mean arterial pressure product, coronary flow velocity decreased by 7 +/- 4% (p < 0.05) and coronary vascular resistance increased by 21 +/- 4% (p < 0.01) 5 min after smoking. There was no change in these variables in the control subjects. CONCLUSIONS: Smoking causes immediate constriction of proximal and distal epicardial coronary arteries and an increase in coronary resistance vessel tone, despite an increase in myocardial oxygen demand. These acute coronary hemodynamic effects may contribute to the adverse cardiovascular consequences of cigarette smoking.

Immunobiological effects of AFB1 and AFB1-FB1 mixture in experimental subchronic mycotoxicoses in rats.

Maize co-contamination with aflatoxin B1 (AFB1) and fumonisin B1 (FB1) is frequently found in several countries. Although the alterations on nutritional and immunologic parameters induced by these mycotoxins, when administered individually, are partially characterised, little is known about the effects induced in animals by a subchronic administration of both toxins mixtures. We have studied the nutritional and immunological alterations induced in rats fed during 90 days with a diet without mycotoxins, containing 40 ppb AFB1, and with a diet containing a mixture of 40 ppb AFB1 and 100 ppm FB1. Animals fed with the mixture of toxins obtained lower body weight than the control ones. The mitogenic response of spleen mononuclear cells (SMC) in vivo was higher in animals fed with AFB1. In in vitro studies, lower proliferations of SMC pre-exposed to AFB1 and to the mixture of toxins were detected. The SMC of animals fed with AFB1 produced lower levels of IL-2, higher of IL-4 and equal levels of IL-10. The SMC of animals fed with both toxins produced higher levels of IL-4, lower of IL-10 and equal levels of IL-2. The SMC preincubated with an AFB1-FB1 mixture produced higher concentrations of IL-4, lower of IL-10 and equal levels of IL-2. The peritoneal macrophages of animals that consumed AFB1 released less H(2)O(2), while animals fed with the mixture of toxins produced higher levels. In in vitro studies, macrophages pre-exposed to the mixture of toxins released less H(2)O(2). These results show different immunobiological effects produced by a mixture of mycotoxins in comparison to the individual action of the same toxins.

Transfer of drug resistance and enterotoxin production in porcine Escherichia coli strains and relationship between K88 antigen and raffinose (melitose) fermentation.

To obtain an indication of the frequency of drug resistance together with enterotoxin production in a select group of porcine E coli strains, those enterotoxigenic strains that were resistant to specific antimicrobial agents were mated as donors with nonenterotoxigenic E coli strains that were sensitive to these drugs as recipients. Seven of the 17 strains tested transferred drug resistance by direct mating. These 7 strains also transferred drug resistance following mobilization. The frequency of recipient conversion was increased following mobilization, as compared with the frequency of conversion resulting from direct mating. In 2 of these strains, enterotoxin production was transferred together with drug resistance. Eight strains transferred drug resistance only after mobilization, and in 2 of these, enterotoxin production was transferred simultaneously with resistance to the antimicrobial agents. In 2 of the 17 strains tested, neither transfer of drug resistance nor transfer of enterotoxin production could be achieved by direct mating or after mobilization. Thirty-nine porcine E coli strains were tested for K88 antigen production and raffinose (melitose) fermentation with a view toward determining whether raffinose fermentation could be used as a diagnostic tool for the detection of the K88 antigen. In 11 of the K88-positive strains tested, only 7 fermented raffinose. In the remaining 28 K88-negative strains, 17 fermented raffinose. Consequently no meaningful correlation existed between these 2 properties of porcine enterotoxigenic E coli strains.

Enterotoxin production and resistance to antimicrobial agents in porcine and bovine Escherichia coli strains.

A select group of porcine and bovine Escherichia coli strains capable of causing diarrheal disease in neonatal pigs and calves, respectively, were tested for enterotoxin production and resistance to 23 different antimicrobial agents. Thirty-four of the 39 porcine strains tested were enterotoxigenic; that is, they synthesized heat-stable (ST), together with heat-labile (LT), enterotoxin; ST toxin alone, or LT toxin alone. Fourteen of the 15 bovine strains tested produced ST toxin only, whereas 1 strain elaborated LT toxin only. All of the strains were multiple drug resistant. Among the porcine strains, 2 were resistant to 6 of the antimicrobial agents, and 1 was resistant to 18 of the drugs. All of these strains were resistant to cloxacillin, lincomycin, and penicillin G. None of them was resistant to chloramphenicol, colistin, gentamicin, polymyxin B, or nalidixic acid. One of the bovine strains was resistant to 7 of the drugs, and 1 strain was resistant to 17 of these antimicrobial agents. All of the bovine strains exhibited resistance to cloxacillin, lincomycin, novobiocin, pencillin G, sulfathiazole, sulfamethizole, and triple sulfa (sulfadiazine, sulfamerazine, and sulfamethazine). None of these strains showed resistance to gentamicin, nalidixic acid, nitrofurazone, or nitrofurantoin.

[Antepartum cardiotocography in high-risk pregnancies and its effect on perinatal morbidity and mortality]. / Cardiotocografía anteparto en embarazos de riesgo elevado y su efecto sobre la morbimortalidad perinatal.

PIP: 2635 prenatal cardiotocographic recordings were correlated with perinatal mortality in 1000 patients. In some cases, there were extenuating circumstances which, when combined with obstetrical intervention, resulted in an increase in mortality. These included congenital malformations, poor maternal conditions for surgery, a hypertensive crisis, and a delay in surgery. The correlated perinatal mortality was 9x1000. (author's modified)^ieng

[Maternal and perinatal morbidity-mortality in pregnant women with renal transplant]. / "Morbimortalidad materna y perinatal en pacientes embarazadas con trasplante renal".

The outcome of 32 pregnancies in renal allograft recipients is reported. The mean age at the time of conception was 27.3 years (range, 20 to 37) with an average interval of 47 months from the time of transplantation to conception (range, 2 to 163). Twenty-nine patients received the graft from a living related donor, one from a living no related donor an 2 from cadaver donors. All patients continued their immunosuppressive regimen during pregnancy and only 6 patients were taking cyclosporine A. Hypertension during pregnancy was observed in 10 patients (31%), superimposed preeclampsia in 4 (14%), preterm labor in 4 (14%) and premature rupture of membranes in 2 (7%). Twenty-eight pregnancies resulted in 28 liveborn infants and there were 4 miscarriages. Cesarean section was performed in 17 cases and 11 had vaginal delivery. Intrauterine growth retardation was observed in 4 cases (14%), fetal distress in 2 (7%) and one neonatal death due to multiple malformations. There was not significative impairment of renal function in this group.

Subchronic mycotoxicoses in Wistar rats: assessment of the in vivo and in vitro genotoxicity induced by fumonisins and aflatoxin B(1), and oxidative stress biomarkers status.

Some evidence suggests that fumonisin B(1) (FB(1)), a worldwide toxic contaminant of grains produced by Fusarium verticillioides, exhibits an oxidative stress mediated genotoxicity. We studied the DNA damage (by the alkaline comet and the micronucleus tests) and biomarkers of cellular oxidative stress (malondialdehyde, MDA; catalase, CAT; and superoxide dismutase, SOD) in spleen mononuclear cells of male Wistar rats subchronically (90 days) fed on a control experimental diet (CED) or poisoned with experimental diets contaminated with a culture material containing 100 ppm of FB(1) (FED), with 40 ppb of aflatoxin B(1) (a common toxic co-contaminant in cereals, AFB(1)ED), and with a mixture of both toxins (MED). The DNA damage was found in 13.7%, 81.7%, 98.0% and 99.3% (comet assay) and in 2.8%, 7.0%, 10.8% and 8.8% (micronucleus technique) in groups CED, FED, AFB(1)ED and MED, respectively. The MDA levels as well as the CAT and SOD activities were increased in all the poisoned animals. A similar behavior was observed in cells exposed in vitro to the toxins. These data support the hypothesis of an oxidative stress mediated genotoxicity induced by FB(1). Furthermore, the extent of DNA damage assessed by the comet assay suggests a possible protective effect of the fumonisins-AFB(1) mixtures in vitro against the genotoxicity induced individually by the toxins.

Depressive disorders and anti-parkinson drug treatment: a case register study.

OBJECTIVE: To estimate the rate of treatment with anti-parkinson drugs (APD) among patients with depression. METHOD: In a nationwide case register linkage study, all persons with a main diagnosis of depression during 5 years were identified. A control group of persons with diagnoses of osteoarthritis was included. The subsequent risk of getting treatment with APD was estimated for the two groups. Statistical analyses involved Poisson's regression and competing risk models. RESULTS: A total of 14 991 persons were included. The rate of getting APD was 2.57 (95% CI: 1.46-4.52) times higher for persons with depression than for persons with osteoarthritis. Overall, the rate was highest for men. However, women with depression had a 3.89 (95% CI: 1.98-7.62) times higher rate of APD treatment as women with osteoarthritis while no significant difference was found among men. CONCLUSION: Provided that prescription of APD reflects the presence of Parkinson's disease, results support a positive statistical association between depressive disorders and Parkinson's disease.

Temporal changes in suicide rates for persons treated and not treated with antidepressants in Denmark during 1995-1999.

OBJECTIVE: To compare the temporal changes in suicide rate among patients treated with antidepressants with the change in suicide rate among persons who have not been treated with antidepressants during 1995-1999. METHOD: In a historic prospective national pharmacoepidemiological register linkage study by using four Danish registers we included 438,625 patients who had purchased antidepressants, and compared them with 1,199,057 population based control persons. The annual rate of suicide was estimated using Poisson regression analyses. RESULTS: The suicide rate decreased for persons treated with antidepressants as well as for persons not treated with antidepressants. The proportion of persons, who committed suicide and who had not been treated with antidepressants decreased. The reduction in suicide rate was more pronounced among persons treated with SSRIs or older antidepressants than among persons not treated with antidepressants. CONCLUSION: Several factors contribute to the decreasing suicide rate. The most pronounced decrease in suicide rate was found among persons treated with antidepressants.

Wave-plate polarizing beam splitter based on a form-birefringent multilayer grating.

We have fabricated a novel device that acts as a quarter-wave plate at normal incidence and as a polarizing beam splitter at an angle of incidence of ~40 deg . The device is made from a multilayer (SiO(2) /Si(3)N(4)) surface-relief zeroth-order one-dimensional grating with a period of 0.3 mum . The device is designed for an operating wavelength of 632.8 nm. We designed the device by using rigorous coupled-wave analysis and fabricated it by direct-write electron-beam lithography and reactive ion etching. Measurements confirmed the performance of the device as a wave plate and as a polarizing beam splitter.

Subwavelength surface-relief gratings fabricated by microcontact printing of self-assembled monolayers.

We have designed and tested subwavelength diffractive optical elements consisting of surface-relief gratings made by microcontact printing of self-assembled monolayers. The first device is a beam deflector for 1.55-mum operation consisting of a surface-relief grating made up of eight pillars over one period (9.3 mum) of the grating. The widths of the pillars vary to approximate a linear phase profile within each grating period. The second device is a quarter-wave plate for 632.8-nm operation consisting of a subwavelength surface-relief grating with a 300-nm period and 58% duty cycle.

Effect of atherosclerosis on cerebral vascular responses to activation of leukocytes and platelets in monkeys.

The goal of this study was to test the hypothesis that atherosclerosis alters responses of cerebral arteries and the ocular circulation to the activation in vivo of leukocytes and platelets. We measured blood flow to the brain and eye using microspheres and pressure in the cerebral microvessels of normal and atherosclerotic monkeys. The intracarotid injection of 10(-7) M N-formyl-L-methionyl-L-leucyl-L-phenylalanine to activate leukocytes did not alter cerebral blood flow in 11 normal or 10 atherosclerotic monkeys but increased the resistance of large cerebral arteries by 46 +/- 11% (mean +/- SEM) in the atherosclerotic animals. The injection of N-formyl-L-methionyl-L-leucyl-L-phenylalanine did not alter blood flow to the eye in 10 normal monkeys but decreased blood flow to the choroid by 38 +/- 9% in 11 atherosclerotic monkeys. The intracarotid injection of 3 x 10(-9) M prostaglandin E2, a leukocyte product, produced an increase in the resistance of large cerebral arteries in five atherosclerotic but not in six normal monkeys. Prostaglandin E2 reduced blood flow to the retina and choroid in the atherosclerotic monkeys by 62 +/- 22% and 65 +/- 17%, respectively. The intracarotid infusion of 25 micrograms/min collagen to activate platelets increased cerebral blood flow by 21 +/- 5% in 10 normal monkeys but did not alter it in 11 atherosclerotic monkeys. Collagen did not alter blood flow to the choroid in 10 normal monkeys but decreased it by 29 +/- 8% in 11 atherosclerotic monkeys.(ABSTRACT TRUNCATED AT 250 WORDS)