The effects of change in lead stimulus modality on the modulation of acoustic blink startle

In two experiments we investigated the effect of generalized orienting induced by changing the modality of the lead stimulus on the modulation of blink reflexes elicited by acoustic stimuli. In Experiment 1 (n = 32), participants were presented with acoustic or visual change stimuli after habituation training with tactile lead stimuli. In Experiment 2 (n = 64), modality of the lead stimulus (acoustic vs. visual) was crossed with experimental condition (change vs. no change). Lead stimulus change resulted in increased electrodermal orienting in both experiments. Blink latency shortening and blink magnitude facilitation increased from habituation to change trials regardless of whether the change stimulus was presented in the same or in a different modality as the reflex-eliciting stimulus. These results are not consistent with modality-specific accounts of attentional startle modulation.

Experimental study of phase equilibria in the systems Fe-Zn-O and Fe-Zn-Si-O at metallic iron saturation

The reported experimental work on the systems Fe-Zn-O and Fe-Zn-Si-O in equilibrium with metallic iron is part of a wider research program that combines experimental and thermodynamic computer modeling techniques to characterize zinc/lead industrial slags and sinters in the system PbO-ZnO-SiO2-CaO-FeO-Fe2O3. Extensive experimental,investigations using high-temperature equilibration and quenching techniques followed by electron probe X-ray microanalysis (EPMA) were carried out. Special experimental; procedures were developed to enable accurate measurements in these ZnO-containing systems to be performed in equilibrium with metallic iron; The systems Fe-Zn-O and FeZn-Si-O were experimentally investigated in equilibrium with metallic iron in the temperature ranges 900 degreesC to 1200 degreesC (1173 to 1473 K) and from 1000 degreesC to 1350 degreesC (1273 to 1623 K), respectively. The liquidus surface in the system Fe-Zn-Si-O in equilibrium with metallic iron was characterized in the composition ranges 0 to 33 wt pet ZnO and 0 to 40 wt pet SiO2. The wustite (Fe,Zn)O, zincite (Zn,Fe)O, willemite (Zn,Fe)(2)SiO4, arid fayalite: (Fe,Zn)(2)SiO4 solid solutions in equilibrium with metallic iron were measured.

Phase and microstructural evolution during the heat treatment of Sm-Ca-alpha-sialon ceramics

The phase and microstructural evolution of multi-cation Sm-Ca-alpha-sialon ceramics was investigated. Six samples were prepared, ranging from a pure Sm-sialon to a pure Ca-sialon, with calcium replacing samarium in 20 eq% increments, thus maintaining an equivalent design composition in all samples. After pressureless sintering at 1820 degreesC for 2 It, all samples were subsequently heat treated up to 192 h at 1450 and 1300 degreesC. The amount of grain boundary glass in the samples after sintering was observed to decrease with increasing calcium levels. A M-ss' or M-ss',-gehlenite solid solution was observed to form during the 1450 degreesC heat treatment of all Sm-containing samples, and this phase forms in clusters in the high-Sm samples. The thermal stability of the alpha-sialon phase was improved in the multi-cation systems. Heat treatment at 1300 degreesC produces SmAlO3 in the high-Sm samples, a M-ss',-gehlenite solid solution in the high-Ca samples, and a Sm-Ca-apatite phase in some intermediate samples. (C) 2002 Elsevier Science Ltd. All rights reserved.

Thermal stability of mixed-cation alpha-sialon ceramics

A series of alpha-sialon (alpha') compositions containing mixed stabilising cations were prepared, by introducing additional CaO to a basic Sm alpha-sialon compositions. The thermal stability of these Sm-Ca-containing alpha-sialon phases was investigated using XRD, SEM and EDXS techniques. It was found that the addition of calcium into the Sm alpha-sialon systems greatly improved the stability of the alpha-sialon phases. Calcium was found to be incorporated into the alpha-sialon structure, coexistent with the samarium, and partitioning of the calcium and samarium was observed between the alpha' phase and grain boundary phases. This indicates a technique which may be used to improve the thermal stability of the alpha' phase while maintaining good refractory phases at the gialon grain boundaries. (C) 2003 Elsevier Science B.V. All rights reserved.

The relationship between prepulse inhibition and perceived intensity of the blink-eliciting stimulus: Stimulus intensity and lead interval effects

The hypothesis that prepulse inhibition of the blink reflex reflects a transient process that protects preattentive processing of the prepulse was investigated. Participants were presented with pairs of blink-eliciting noises, with some noises preceded by a prepulse, and were asked to rate the intensity of the second noise relative to the first. Inhibition of blink amplitude was greater for a 110 dB(A) noise than for a 95 dB(A) noise with a 120 ms lead interval, whereas there was no difference with a 30 ms lead interval. The reduction in perceived intensity was greater for the 110 dB(A) noise than for the 95 dB(A) noise with the 120 ms lead interval, but not with the 30 ms lead interval. The parallel results support an association between prepulse inhibition and perceived intensity. However, the prepulse did not reduce intensity ratings relative to control trials in some conditions, suggesting that prepulse inhibition is not always associated with an attenuation of the impact of the blink-eliciting stimulus.

First detection of lead in black paper from intraoral film An environmental concern

Lead (Pb) contamination in the black paper that recovers intraoral films (BKP) has been investigated. BKP samples were collected from the Radiology Clinics of the Dental School of Ribeirao Preto, University of Sao Paulo, Brazil. For sake of comparison, four different methods were used. The results revealed the presence of high lead levels, well above the maximum limit allowed by the legislation. Pb contamination levels achieved after the following treatments: paper digestion in nitric acid, microwave treatment, DIN38414-54 method and TCLP method were 997 mu g g(-1), 189 mu g g(-1), 20.8 mu g g(-1), and 54.0 mu g g(-1), respectively. Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICP-MS) were employed for lead determination according to the protocols of the applied methods. Lead contamination in used BKP was confirmed by scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS). All the SEM imaging was carried out in the secondary electron mode (SE) and backscattered-electron mode (QBSD) following punctual X-ray fluorescence spectra. Soil contamination derived from this product revealed the urgent need of addressing this problem. These elevated Pb levels, show that a preliminary treatment of BKP is mandatory before it is disposed into the common trash. The high lead content of this material makes its direct dumping into the environment unwise. (C) 2009 Elsevier B.V. All rights reserved.

Electron paramagnetic resonance of Ni(II) doped tris(ethylenediamine)zinc(II) dinitrate

Variable temperature electron paramagnetic resonance spectra of tris(ethylenediamine)zinc(II) dinitrate single crystals doped with NI(II) have been measured. The host crystal undergoes a trigonal to monoclinic phase transition at 146 K. Above the transition temperature the zero field splitting tensor is axially symmetric with D = -0.831 cm(-1) and below it becomes rhombic with D = -0.785 cm(-1), E = -0.088 cm(-1). The low temperature spectrum is characterised by the pattern repeating every 60 degrees when the crystal is rotated about the high temperature c axis. The analysis shows that the Zn(II) site retains a C-2 symmetry axis and that the distortion away from the D-3 site symmetry observed for high temperatures is small, the principal axes being tilted by 2.6 degrees. This implies that the phase transition involves the flipping of the C-C backbone in one of the ethylenediamine ligands of the complex, resulting in a A delta delta delta to Lambda delta delta lambda type conformational change.

Tris(ethylenediamine-N,N')zinc(II) dinitrate

The Zn-II atom in [Zn(C2H8N2)(3)](NO3)(2) has a distorted octahedral geometry of D-3 symmetry With three ethylenediamine bidentate Ligands completing the coordination.

Egr transcription factors in the nervous system

The Egr proteins, Egr-1, Egr-2, Egr-3 and Egr-4, are closely related members of a subclass of immediate early gene-encoded, inducible transcription factors. They share a highly homologous DNA-binding domain which recognises an identical DNA response element. In addition, they have several less-well conserved structural features in common. As immediate early proteins, the Egr transcription factors are rapidly induced by diverse extracellular stimuli within the nervous system in a discretely controlled manner. The basal expression of the Egr proteins in the developing and adult rat brain and the induction of Egr proteins by neurotransmitter analogue stimulation, physiological mimetic and brain injury paradigms is reviewed. We review evidence indicating that Egr proteins are subject to tight differential control through diverse mechanisms at several levels of regulation. These include transcriptional, translational and posttranslational (including glycosylation, phosphorylation and redox) mechanisms and protein-protein interaction. Ultimately the differentially co-ordinated Egr response may lead to discrete effects on target gene expression. Some of the known target genes of Egr proteins and functions of the Egr proteins in different cell types are also highlighted. Future directions for research into the control and function of the different Egr proteins are also explored. (C) 1997 Elsevier Science Ltd.

Supplementation of Vitamin E, Vitamin C, and Zinc Attenuates Oxidative Stress in Burned Children: A Randomized, Double-Blind, Placebo-Controlled Pilot Study

The aim of this study was to investigate the effect of supplementation of vitamin E, vitamin C, and zinc on the oxidative stress in burned children. In a prospective double-blind placebo-controlled pilot study, 32 patients were randomized as no supplementation (n = 15) or antioxidant supplementation (n = 17) groups. Supplementation consisted of the antioxidant mixture of vitamin C (1.5 times upper intake level), vitamin E (1.35 times upper intake level), and zinc (2.0 times recommended dietary allowance) administered during 7 days starting on the second day of admittance into the hospital. Energy requirement was calculated by the Curreri equation, and protein input was 3.0 g/kg of ideal body mass index (percentile 50 degrees). Total antioxidant capacity of plasma and malondialdehyde were used to monitor oxidative stress. The time of wound healing was evaluated as the main clinical feature. Patients (age 54.2 +/- 48.9 months, 65.6% males), who exhibited 15.5 +/- 6.7% of total burn area, showed no differences in age and sex, when compared with controls. Intake of the administered antioxidants was obviously higher in treated subjects (P = .005), and serum differences were confirmed for vitamin E and C, but not for zinc (P = .180). There was a decrease in lipid peroxidation (malondialdehyde level) (P = .006) and an increase in vitamin E concentrations in the antioxidant supplementation group (P = .016). The time of wound healing was lower in the supplemented group (P < .001). The antioxidant supplementation through vitamin E and C and the mineral zinc apparently enhanced antioxidant protection against oxidative stress and allowed less time for wound healing. (J Burn Care Res 2009;30:859-866)

Lead Poisoning by Intradiscal Firearm Bullet A Case Report

Study Design. The report of a rare case of lead poisoning by an intradiscal firearm bullet is presented. Objective. To describe and discuss the clinical and radiologic features (by computed tomography and magnetic resonance imaging) of a gunshot wound in the L2-L3 space which caused lead poisoning 5 years afterwards. Summary of Background Data. Lead poisoning from firearm bullets is rare, but the possibility should be investigated in the case of bullets lodged in the joints. Methods. A 30-year-old man presented to the emergency room with an intense lumbar pain complaint, colic, intestinal constipation, insomnia, and progressive headache for 20 days. He had a history of a gunshot wound 5 years previously, and the bullet was left in situ, in the intravertebral disc between L2 and L3, as confirmed by radiographs, computed tomography, and magnetic resonance imaging. The hypothesis of lead poisoning was confirmed by the laboratory results. Chelation treatment with calcium versenate (disodium ethylenediaminetetraacetate, or CaNa (2) EDTA) was indicated. The patient was admitted and treated once again, before surgical removal of the bullet. Results. After removal of the bullet, the patient had an episode of recurrence, and a new chelation cycle was performed, with complete resolution. Conclusion. Lead poisoning can result in severe clinical disorders that require rapid treatment. In this case, both clinical and surgical treatments led to complete resolution of the symptoms.

Intrauterine Growth Restriction and Zinc Concentrations in Term Infants during the First Month of Life

Objective: We analyzed the influence of IUGR on the concentrations of plasma (Znpl) and erythrocyte (Zne) zinc and on the ratios of Zne to Znpl (Zne:Znpl) and Zne to hemoglobin (Zne:Hb) in term infants during the first month of life. Design: Cohort study. Setting: Tertiary Care Neonatal Unit. Subjects: Exclusively breastfed term newborns (n = 84) were divided into 3 groups: group 1, without IUGR (n = 41), group II. with mild to moderate IUGR (n = 12). and group III, with severe IUGR (n = 31). IUGR was defined as birth weight under the 5th percentile of the Alexander et at curve and as a Kramer Index (KI: ratio of birth weight to estimated weight for each gestational age) <0.85. Severe IUGR was defined as a KI <0.75. Znpl, Zne. and Hb were measured at birth. 3 days, and 1 month of life. Results: Znpl tended to decrease (P = 0.073), Zne and Zne:Znpl increased (P < 0.001), and Hb decreased (P < 0.001) during the first month of life. There was not Znpl, Zne and Zne:Znpl time by group interaction. Zne:Hb increased (P < 0.001) during the first month of life and was lower in Group II at I month of age. Differences between Groups I and If (P = 0.017) and Groups II and III at I month of age (P = 0.011) were detected. Conclusions: Our results suggest that IUGR did not have association with erythrocyte zinc and Zne:Hb ratio at birth. However. neonatal nutrition could have influenced zinc incorporation during this period, through Zne increase.

Esophageal cancer associated with chronic mucocutaneous candidiasis. Could chronic candidiasis lead to esophageal cancer?

Chronic mucocutaneous candidiasis (CMC) is a rare disease associated with immunodeficiency and characterized by persistent and refractory infections of the skin, appendages and mucous membranes caused by members of the genus Candida. Several different disorders are classified under this common denominator, including chronic and recurrent mucocutaneous infections due to Candida spp., which are sometimes linked to autoimmune endocrinopathies. These fungal infections are usually confined to the mucocutaneous surface, with little propensity for systemic disease or septicemia. We describe a patient with CMC who had an esophageal candidiasis refractory to treatment for decades and who developed an epidermoid esophageal cancer. No risk factors such as familiar susceptibility, smoking, alcohol drinking, or living in an endemic area were verified. This case report suggests the participation of nitrosamine compounds produced by chronic Candida infections as a risk factor for esophageal cancer in a patient with autosomal-dominant chronic mucocutaneous candidiasis.