Phytochemical characterization and evaluation of anticataract potential of seabuckthorn leaf extract.

Objective: This study was undertaken to carry out phytochemical characterization of aqueous extract of Seabuckthorn (SBT, Hippophae rhamnoides L.) leaves and evaluation of its therapeutic role in oxidative stress-induced cataract in isolated goat lenses using Vit. E as reference compound.

Cyanobacteria in wetlands of the industrialized Sambalpur District of India.

Background: Cyanobacteria are common components of phytoplankton communities in most freshwater ecosystems. Proliferations of cyanobacteria are often caused by high nutrient loading, and as such can serve as indicators of declining water quality. Massive industrialization in developing countries, like India, has polluted fresh water bodies, including wetlands.

Traumatic hemisection and restoration of a maxillary first premolar: a case report.

Surgical hemisection of a tooth involves the deliberate excision of one or more roots and their associated coronal structure. This procedure generally is performed as an alternative to complete extraction on molars when their prognosis can be improved by removing roots that are significantly compromised. Traumatic hemisection is nondeliberate and describes complete fracture through a furcation, resulting in severance of a fragment from the tooth.

Effect of illumination on the accuracy of identifying interproximal carious lesions on bitewing radiographs.

Background: Dentists generally use a viewbox as the primary source of illumination when examining radiographs. Secondary sources of illumination (i.e.

Effect of partial volume correction on estimates of the influx and cerebral metabolism of 6-[(18)F]fluoro-L-dopa studied with PET in normal control and Parkinson's disease subjects.

The poor spatial resolution of positron emission tomography (PET) is a limiting factor in the accurate assay of physiological processes investigated by compartmental modeling of tracer uptake and metabolism in living human brain. The radioactivity concentration in a region-of-interest is consequently altered by loss of signal from that structure and contamination from adjacent brain regions, phenomena known as partial volume effects. We now apply an MRI-based algorithm to compensate for partial volume effects in the special case of compartmental modeling of the cerebral uptake of 6-[(18)F]fluoro-L-dopa (FDOPA), an exogenous substrate of dopa decarboxylase.

Stimulation of dopa decarboxylase activity in striatum of healthy human brain secondary to NMDA receptor antagonism with a low dose of amantadine.

The efficacy of amantadine in alleviating motor symptoms of Parkinson's disease may be mediated in part by stimulation of cerebral dopa decarboxylase (DDC) activity, secondary to antagonism of N-methyl-D-aspartate (NMDA) type glutamate receptors. We tested the specific hypothesis that amantadine increases the decarboxylation rate of 6-[(18)F]fluoro-L-DOPA (FDOPA), an exogenous substrate for DDC, in healthy human brain. Radioactivity concentrations in brain tissue of neurologically normal volunteers (n = 5) injected intravenously with FDOPA ( approximately 4.

Pharmacokinetics of radiotracers in human plasma during positron emission tomography.

Many radiopharmaceuticals for positron emission tomography (PET) are substantially metabolized in peripheral organs. Pharmacological treatments intended to alter cerebral metabolism might also alter radiotracer metabolism, consequently altering the cerebral uptake. First-order rate constants for the metabolism of PET tracers can be calculated by a linear graphical method from the precursor and metabolite concentrations measured in plasma extracts fractionated by HPLC.

The kinetic behaviour of [3H]DOPA in living rat brain investigated by compartmental modelling of static autoradiograms.

The kinetic behaviour of [3H]DOPA in living rat brain was investigated by compartmental modelling of measured activities from combined metabolite pools in a time-series (180 min) of static autoradiograms from right cerebral hemispheres. Two models of [3H]DOPA uptake and metabolism that incorporated the removal of the decarboxylation product, [3H]dopamine, from brain were significantly more accurate than a model in which [3H]dopamine accumulated irreversibly in situ. Present estimates of [3H]DOPA kinetic constants were compared to previously published results based on the analysis of measured activities from individual metabolite pools separated by chromatographic fractionation of [3H]DOPA metabolites in the left cerebral hemispheres of the same rats.

On the accuracy of an [18F]FDOPA compartmental model: evidence for vesicular storage of [18F]fluorodopamine in vivo.

The biological accuracy of a nonlinear compartmental model describing the in vivo kinetics of L-3,4-dihydroxy-6-[18F]fluorophenylalanine ([18F]FDOPA) metabolism was investigated. Tissue activities for [18F]FDOPA and its labeled metabolites 3-O-methyl-[18F]FDOPA ([18F]OMFD), 6-[18F]fluorodopamine ([18F]FDA), L-3,4-dihydroxy-6-[18F]fluorophenylacetic acid ([18F]FDOPAC), and 6-[18F]fluorohomovanillic acid ([18F]FHVA) were calculated using a plasma [18F]FDOPA input function, and kinetic constants estimated previously by chromatographic fractionation of 18F-labeled compounds in plasma and brain extracts from rat. Present data accurately reflected the measured radiochemical composition in rat brain for tracer circulation times past 10 min.