167 research outputs found

    Amino Acids and N-acetyl-aspartyl-glutamate as Neurotransmitter Candidates in the Monkey Retinogeniculate Pathways

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    The lateral geniculate nucleus (LGNd) receives chemically identified inputs from brain stem structures, the thalamus and visual cortex. The identity of the neurotransmitter(s) in the retinal input, however, is unknown. To investigate the possibility that some amino acids and certain dipeptides, such as N-acetyl-aspartyl-glutamate (NAAG), fulfill this function, changes in their concentration were measured in the optic tract, parvocellular and magno-cellular segments of the LGNd, superior colliculus and visual cortex of six monkeys (Macaca fascicularis), seven days after right optic tractotomy. The LGNd was studied also in two additional macaques, three months after occipital lobectomy. Tissue was frozen within five minutes of death, regions were dissected with the micropunch technique, and substances were analyzed by HPLC. Of the ten compounds measured in the normal side, glutamate, glutamine, glycine, and alanine had homogeneous distributions. GABA was highest in the superior colliculus, cystathionine and NAAG decreased in the rostrocaudal direction, and N-acetyl-aspartate showed an opposite gradient of concentration. The heterogeneity in taurine and aspartate was less systematic. Optic tract section induced significant, large reductions in NAAG, glutamate and aspartate in the optic tract distal to the lesion. Significant decreases in NAAG, and to a lesser extent in glutamate, were observed in the LGNd. Changes in the dipeptide were apparent in both the parvocellular and magnocellular segments. Reductions in glutamate reached significance in the parvocellular laminae, and those of aspartate approached significance in the magnocellular division. No significant differences were detected in the superior colliculus and striate cortex. Occipital lobectomy produced large declines in aspartate and glutamate in the LGNd, as well as moderate reductions in alanine and GABA, and minor changes in glutamine and glycine. The results of optic tractotomy support the role of NAAG as a neurotransmitter candidate in the monkey retinogeniculate pathways; its significant decrease in both geniculate segments suggests that X- and Y- retinal axons utilize this substance. Although at times the reductions in glutamate or aspartate failed to reach significance, their role cannot be excluded. The findings after occipital lobectomy strongly favor these latter substances as corticogeniculate transmitters

    1.5V fully programmable CMOS Membership Function Generator Circuit with proportional DC-voltage control

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    A Membership Function Generator Circuit (MFGC) with bias supply of 1.5 Volts and independent DC-voltage programmable functionalities is presented. The realization is based on a programmable differential current mirror and three compact voltage-to-current converters, allowing continuous and quasi-linear adjustment of the center position, height, width and slopes of the triangular/trapezoidal output waveforms. HSPICE simulation results of the proposed circuit using the parameters of a double-poly, three metal layers, 0.5 μm CMOS technology validate the functionality of the proposed architecture, which exhibits a maximum deviation of the linearity in the programmability of 7 %

    Ultra Low-Power Analog Median Filters

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    The design and implementation of three analog median filter topologies, whose transistors operate in the deep weak-inversion region, is described. The first topology is a differential pairs array, in which drain currents are driven into two nodes in a differential fashion, while the second topology is based on a wide range OTA, which is used to maximize the dynamic range. Finally, the third topology uses three range-extended OTAs. The proposed weak-inversion filters were designed and fabricated in ON Semiconductor 0.5 micrometer technology through MOSIS. Experimental results of three-input fabricated prototypes for all three topologies are show, where power consumptions of 90nW in the first case, and 270nW in the other two cases can be noticed. A dual power supply +/-1.5 Volts were used

    Concurrent Chorioptic Mange and Dermatophytosis in Dairy Goats: A Case Report

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    SIMPLE SUMMARY: Chorioptes mites are particularly common in goats, with infestations usually subclinical and often asymptomatic. In the present case, many animals had a severe clinical presentation, possibly due to the associated dermatophyte infection (Trichophyton verrucosum), since a concurrent or underlying disease may exacerbate clinical response. Goats were treated topically with pour-on Eprinomectin (1 mg/kg), while an enilconazole solution was used for environmental disinfection against dermatophyte spores. ABSTRACT: A concurrent chorioptic mange and dermatophytosis outbreak occurred in a goat flock in northwestern Italy. Sanitation of the flock was obtained following pour-on eprinomectin application at a dose of 1 mg/kg; enilconazole was used for environmental disinfection against dermatophyte spores

    TEG® and RapidTEG® are unreliable for detecting warfarin-coagulopathy: a prospective cohort study

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    BACKGROUND: Thromboelastography® (TEG) utilizes kaolin, an intrinsic pathway activator, to assess clotting function. Recent published studies suggest that TEG results are commonly normal in patients receiving warfarin, despite an increased International Normalized Ratio (INR). Because RapidTEG™ includes tissue factor, an extrinsic pathway activator, as well as kaolin, we hypothesized that RapidTEG would be more sensitive in detecting a warfarin-effect. METHODS: Included in this prospective study were 22 consecutive patients undergoing elective cardioversion and receiving warfarin. Prior to cardioversion, blood was collected to assess INR, Prothrombin Time, TEG, and RapidTEG. RESULTS: INR Results: 2.8 ± 0.5 (1.6 to 4.2). Prothrombin Time Results: 19.1 ± 2.2 (13.9. to 24.3). TEG Results (Reference Range): R-Time: 8.3 ± 2.7 (2–8); K-Time: 2.1 ± 1.4 (1–3); Angle: 62.5 ± 10.3 (55–78); MA: 63.2 ± 10.3 (51–69); G: 9.4 ± 3.5 (4.6-10.9); R-Time within normal range: 10 (45.5%) with INR 2.9 ± 0.3; Correlation coefficients for INR and each of the 5 TEG variables were insignificant (P > 0.05). RapidTEG Results (Reference Range): ACT: 132 ± 58 (86–118); K-Time: 1.2 ± 0.5 (1–2); Angle: 75.4 ± 5.2 (64–80); MA: 63.4 ± 5.1 (52–71); G: 8.9 ± 2.0 (5.0-11.6); ACT within normal range: 9 (40.9%) with INR 2.7 ± 0.5; Correlation coefficients for INR and each of the 5 RapidTEG variables were insignificant (P > 0.05). CONCLUSIONS: TEG, using kaolin activation, and RapidTEG, with kaolin and tissue factor activation, were normal in a substantial percent of warfarin patients, despite an increased INR. The false-negative rate for detecting warfarin coagulopathy with either test is unacceptable. The lack of correlation between INR and all TEG and RapidTEG components further indicates that these methodologies are insensitive to warfarin effects. Findings suggest that intrinsic pathway activation may mitigate detection of an extrinsic pathway coagulopathy

    Situation of HIV infections and STIs in the United Kingdom in 2007.

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    In the United Kingdom (UK) in 2007, an estimated 77,400 persons were living with human immunodeficiency virus (HIV) of whom 28% are unaware of their infection. A total of 7,734 persons were newly diagnosed with HIV infection in 2007, of which 31% were diagnosed late. This highlights the need for wider HIV testing, especially in those areas with a high diagnosed prevalence, as recommended in recent national guidelines. Among newly diagnosed cases of HIV in 2007, 41% acquired their infection through sex between men (four in five of whom acquired their infection in the UK) and 55% through heterosexual contact (four in five of whom acquired their infection abroad, mainly in sub-Saharan Africa). Young persons aged 16 to 24 years are disproportionally affected by sexually transmitted diseases (STIs) accounting for 65% of genital chlamydia infections, 50% of cases of genital warts and 50% of cases of gonorrhoea that were diagnosed in 2007

    Spatiotemporal Imaging of Zinc Ions in Zebrafish Live Brain Tissue Enabled by Fluorescent Bionanoprobes

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    The zebrafish is a powerful model organism to study the mechanisms governing transition metal ions within whole brain tissue. Zinc is one of the most abundant metal ions in the brain, playing a critical pathophysiological role in neurodegenerative diseases. The homeostasis of free, ionic zinc (Zn2+) is a key intersection point in many of these diseases, including Alzheimer’s disease and Parkinson’s disease. A Zn2+ imbalance can eventuate several disturbances that may lead to the development of neurodegenerative changes. Therefore, compact, reliable approaches that allow the optical detection of Zn2+ across the whole brain would contribute to our current understanding of the mechanisms that underlie neurological disease pathology. We developed an engineered fluorescence protein-based nanoprobe that can spatially and temporally resolve Zn2+ in living zebrafish brain tissue. The self-assembled engineered fluorescence protein on gold nanoparticles was shown to be confined to defined locations within the brain tissue, enabling site specific studies, compared to fluorescent protein-based molecular tools, which diffuse throughout the brain tissue. Two-photon excitation microscopy confirmed the physical and photometrical stability of these nanoprobes in living zebrafish (Danio rerio) brain tissue, while the addition of Zn2+ quenched the nanoprobe fluorescence. Combining orthogonal sensing methods with our engineered nanoprobes will enable the study of imbalances in homeostatic Zn2+ regulation. The proposed bionanoprobe system offers a versatile platform to couple metal ion specific linkers and contribute to the understanding of neurological diseases

    A School-Based Program to Promote Well-Being in Preadolescents: Results From a Cluster Quasi-Experimental Controlled Study

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    Diario della Salute [My Health Diary] is a school-based program designed to enhance the subjective well-being and health of 12- to 13-year-old students. We hypothesized that providing students with the social and emotional skills to fulfill their potential and deal with common developmental tasks of adolescence (e.g., onset of puberty, identity development, increased responsibilities and academic demands) would result in improved well-being and health. The program comprises five standardized interactive lessons concerning common psychosocial and health issues in adolescence, and two narrative booklets addressed to both students and their parents. We evaluated the effectiveness of the program in terms of the students' subjective well-being, aggressive behavior, and health behavior. Using a quasi-experimental study design, schools in the intervention group implemented the full program and those in the comparison group received their regular curriculum. We administered measures of the study's objectives both before and after program implementation. Statistical analyses accounted for within-school clustering, potential socioeconomic and demographic confounding, and pre-implementation levels of these measures. We sampled 62 schools and allocated 2630 students to either an intervention or comparison group. Sociodemographic characteristics and baseline outcomes were balanced across study groups. Unexpectedly, respondents in the intervention group had 0.38 greater mean adjusted score of the WHO/Europe Health Behaviour in School-Aged Children Symptom Checklist instrument than respondents in the comparison group, indicating a reduction in subjective well-being. We did not observe any program effects on aggressive and health behaviors. The apparent reduction in subjective well-being reflected by an increased perception of psychosomatic complaints is suggestive of either increased emotional competence or, potentially, iatrogenic program effects. While greater emotional competence is positively associated with well-being over the course of life, the program in its present form should not be disseminated due to the possibility of adverse unintended effects
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