Influences of aspartate on circadian patterns of lipid peroxidation products and antioxidants in Wistar rats

INTRODUCTION: The aim of the present study was to demonstrate the effects of aspartate on the circadian patterns of lipid peroxidation products and antioxidants in aspartate-treated rats, in order to investigate the influences of aspartate and whether it could modulate these rhythms differently, since aspartate is an important excitatory neurotransmitter (present in retinohypothalamic tract and suprachiasmatic nuclei [SCN]) involved in the generation and regulation of circadian rhythmicity. METHODS: Aspartate (50 mg/kg body weight) was administered orally for 60 days to Wistar rats, and 24-hour rhythms of thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH), superoxide dismutase (SOD) and catalase were studied under semi-natural (light/dark 12:12 hr) conditions. RESULTS: Exogenous aspartate administration caused acrophase advances in TBARS rhythms, and delays in GSH, SOD and catalase rhythms; altered MESOR and decreased amplitude values were also seen in all of these rhythms. CONCLUSION: Our findings indicate that the orally-treated aspartate could reach the hypothalamus, and various brain centres possibly including SCN, and could modulate the circadian patterns of lipid peroxidation products and antioxidants.     

Post annealing induced manipulation of phase and upconversion luminescence of Cr3+ doped NaYF4:Yb,Er crystals

The role of post synthesis annealing at different temperatures (200–600 °C) on the structural as well as luminescence properties of NaY_80%F₄:Yb_17%,Er_3% prepared via a coprecipitation method was found to change the structure from a cubic to hexagonal phase with a concomitant increase in upconversion luminescence by 12 times for the green region and 17 times for the red region. Addition of the Cr³⁺ ions (5–20 mol%) into the host followed by post annealing at 200–600 °C causes that the samples to exhibit phase dependent and upconversion luminescence behavior that depend upon the doping concentration as well as the annealing temperature. The inductively coupled optical emission spectroscopy reveals that only 1/600 times of the desired volume of the co-dopant goes to the lattice and it can manifest visible spectral changes in the diffuse reflectance spectra of the samples. The samples co-doped with Cr³⁺ ion concentrations of 10–15% and post-annealed at 600 °C were found to have maximum emission with an enhancement factor of 24 for the green region and 33 for the red region. In addition, the laser power dependent studies reveal that even for the power density levels 3.69 W cm⁻² to 32.14 W cm⁻², the samples are in the saturation regime and most of the samples investigated here follow a single photon process, and a few samples show a slope value less than 1 for laser power dependent intensity plots. The results show the remarkable promise of controlled tailoring of the properties of upconversion crystals via post annealing and co-doping.

Co-dopant (Cr³⁺ ion) concentration as well as post annealing found to change the structural as well as luminescence properties of Cr³⁺ ion doped NaY_80%F₄:Yb_17%,Er_3% prepared via a co-precipitation method.     

Determination of reference values for optical properties of liquid phantoms based on Intralipid and India ink

A multi-center study has been set up to accurately characterize the optical properties of diffusive liquid phantoms based on Intralipid and India ink at near-infrared (NIR) wavelengths. Nine research laboratories from six countries adopting different measurement techniques, instrumental set-ups, and data analysis methods determined at their best the optical properties and relative uncertainties of diffusive dilutions prepared with common samples of the two compounds. By exploiting a suitable statistical model, comprehensive reference values at three NIR wavelengths for the intrinsic absorption coefficient of India ink and the intrinsic reduced scattering coefficient of Intralipid-20% were determined with an uncertainty of about 2% or better, depending on the wavelength considered, and 1%, respectively. Even if in this study we focused on particular batches of India ink and Intralipid, the reference values determined here represent a solid and useful starting point for preparing diffusive liquid phantoms with accurately defined optical properties. Furthermore, due to the ready availability, low cost, long-term stability and batch-to-batch reproducibility of these compounds, they provide a unique fundamental tool for the calibration and performance assessment of diffuse optical spectroscopy instrumentation intended to be used in laboratory or clinical environment. Finally, the collaborative work presented here demonstrates that the accuracy level attained in this work for optical properties of diffusive phantoms is reliable.OCIS codes: (170.5280) Photon migration, (170.7050) Turbid media, (170.3890) Medical optics instrumentation     

Spontaneous gastric rupture in infants and children

Rupture of the stomach in infants and children is probably the end result of a variety of causes, singly or in combination. It is possible to determine the cause of the lesion in many cases where processes basically similar to those observed in other age groups can be identified. However, there still remains a group with truly idiopathic “spontaneous” rupture. Formerly well entrenched beliefs, such as the existence of congenital anomalies of the musculature of the stomach, are no longer tenable. At present, mechanical forces are suspected of having a central role in the development of “spontaneous” rupture. The proposed theoretical mechanisms and their anatomic basis as illustrated by 2 cases have been reviewed, but experimental proof is needed before one can accept these postulates without reserve.     

Zur Datenqualit?t der Medizinischen Statistik VESKA

Zusammenfassung Es werden Methode und Resultate einer Studie zur Datenqualität der Medizinischen Statistik VESKA vorgestellt, und die Faktoren beschrieben, welche den Unterschieden in der Codierung klinischer Angaben zugrunde liegen. Daraus können Richtlinien zur Anwendung von Korrekturfaktoren für die Interpretation dieser Statistik abgeleitet werden.

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Data quality in the VESKA/Hospital Discharge Data Base

Summary Methods and results of a study on the reliability of data of the VESKA Hospital Discharge Data Base are presented. At least 95% of the hospital discharges are reported by the participants. There exist different agreement levels of diagnoses between the original VESKA file and a control codification. The major factors which influence these differences are described and general directions for the application of correcting factors derived which can contribute to a better interpretation of this statistical program.

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La qualité des données de la Statistique médicale VESKA

Résumé Le travail présente la méthode et les résultats d'une étude sur la qualité des données de la Statistique médicale VESKA. Au moins 95% des hospitalisations sont relevées par les participants à cette statistique. Les taux de concordance entre la fiche VESKA et la codification de côntrole varient sous l'influence de plusieurs facteurs. Les résultats permettent de proposer des directives pour l'application de facteurs de correction qui peuvent contribuer à une meilleure interprétation de cette statistique.

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mit Unterstützung des Schweiz. Nationalfonds zur Förderung der wissenschaftlichen Forschung, Projekt Nr. 3.911-083.     

Molecular analysis of fluoroquinolone-resistant Salmonella Paratyphi A isolate, India

Salmonella enterica serovar Paratyphi A is increasingly a cause of enteric fever. Sequence analysis of an Indian isolate showed a unique strain with high-level resistance to ciprofloxacin associated with double mutations in the DNA gyrase subunit gyrA (Ser83-->Phe and Asp87-->Gly) and a mutation in topoisomerase IV subunit parC (Ser80-->Arg).