Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Neuromelanin (NM) is a complex polymer pigment foundprimarily in the dopaminergic neurons of the human substantia nigra. Thestructure of NM is only partially characterized, and its synthesis pathwayremains unknown. We used nuclear magnetic and infrared spectroscopy to examinethe structure of human NM isolated from the substantia nigra compared withsynthetic dopamine melanins. Biochemical analyses were used to investigateproteinaceous and dopaminergic components in these samples. Following acidhydrolysis of NM samples, small amounts of DOPA, dopamine, and a variety ofamino acids were measured. These findings suggest a peptide component in NMstructure. NM also appears to contain a variety of unidentified structuralcomponents possibly derived from the oxidation of dopamine. Human NM differsstructurally from synthetic dopamine melanin, but both human and synthetic NMinclude an aromatic backbone. It is interesting that both human NM andsynthetic melanin also contain a large proportion of aliphatic structures. Ourresults suggest that NM is a more complex pigment than synthetic dopaminemelanin formed via dopamine autoxidation alone.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 36 (1981), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The properties of carnitine transport were studied in rat brain slices. A rapid uptake system for carnitine was observed, with tissue-medium gradients of 38 ± 3 for L-[14CH3]carnitine and 27 ± 3 for D-[14CH3]carnitine after 180 min incubation at 37°C in 0.64 mM substrate. Uptake of L- and D-carnitine showed saturability. The estimated values of Km for L- and D-carnitine were 2.85 mM and 10.0 mM, respectively; but values of Vmax (1 μmol/min/ml in-tracellular fluid) were the same for the two isomers. The transport system showed stereospecificity for L-carnitine. Carnitine uptake was inhibited by structurally related compounds with a four-carbon backbone containing a terminal carboxyl group. L-Carnitine uptake was competitively inhibited by γ-butyrobetaine (Ki= 3.22 mM), acetylcarnitine (Ki= 6.36 mM), and γ-aminobutyric acid (Ki= 0.63 mM). The data suggest that carnitine and γ-aminobutyric acid interact at a common carrier site. Transport was not significantly reduced by choline or lysine. Carnitine uptake was inhibited by an N2 atmosphere, 2,4-dinitrophenol, carbonylcyanide-N-chlorophenylhydrazone, potassium cyanide, n-ethylmaleimide, and ouabain. Transport was abolished by low temperature (4°C) and absence of glucose from the medium. Carnitine uptake was Na+-dependent, but did not require K+ or Ca2+.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Prostaglandins 13 (1977), S. 901-907 
    ISSN: 0090-6980
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Medicine
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 82 (1991), S. 39-44 
    ISSN: 1432-0533
    Keywords: AIDS ; Substantia nigra ; Histopathology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using stereological techniques we have estimated the volume density of melanin and counted the number of pigmented and non-pigmented neuronal cell bodies in the pars compacta of the substantia nigra of 12 autopsied patients with acquired immune deficiency syndrome (AIDS) who did not have inflammation or necrosis of the midbrain or clinical parkinsonism. The total number of neuronal cell bodies was 25% lower in AIDS (P〈0.01) than in 12 age-matched controls, although the volume density of neuronal melanin did not differ from that of controls because the percentage of pigmented cell bodies was higher (P〈0.01) and the cell bodies were more fully packed with melanin in AIDS. Also, the expected increase with age of the volume density of neuronal melanin (P〈0.02) and the percentage of pigmented neurons (P〈0.01) occurred in the controls but not in AIDS patients. Importantly, our histopathological examination showed unequivocal nigral degeneration with neuronal loss, small neuronal cell bodies packed with melanin, reactive astrocytosis and extra-cellular melanin in the AIDS patients but not in controls. Our study shows that a subclinical nigral degeneration is common in AIDS and could possibly explain the heightened suspectibility of some patients to drug-induced parkinsonism.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 28 (1985), S. 495-499 
    ISSN: 1432-1041
    Keywords: pinacidil ; hypertension ; plasma catecholamines ; plasma renin activity ; diuretic drugs ; side-effects ; hydrochlorothiazide ; amiloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Pinacidil, a new cyanoguanidine derivative, is an antihypertensive agent with arteriolar vasodilating properties, which acts on precapillary resistance vessels. A trial was carried out in 30 patients with essential hypertension WHO I-II. The treatment period was divided into three phases. Hydrochlorothiazide (HCTZ) and amiloride were administered for 4 weeks in Phase 1 and supine and standing blood pressure decreased significantly. During Phase 2 pinacidil was added to HCTZ/amiloride for the following 3 months. A further significant reduction in blood pressure was obtained. In the next period of treatment (Phase 3) patients were divided into two groups. For 1 month Group A (15 patients) received pinacidil alone and Group B (15 patients) received HCTZ/amiloride. Conventional laboratory blood tests in all patients remained unchanged during treatment. Reported side effects during Phase 2 were headache (2 patients), dizziness (3 patients), palpitations (2 patients) and ankle oedema (2 patients). Plasma renin activity was slightly increased at the end both of Phases 1 and 2. Plasma catecholamines were increased but not significantly at the end of Phase 2 as compared to Phase 1. The results indicate that pinacidil is effective in lowering blood pressure in mild to moderate essential hypertension.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Cardiovascular drugs and therapy 4 (1990), S. 265-268 
    ISSN: 1573-7241
    Keywords: parasympathetic activity ; hypertension ; enalapril
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To evaluate the effect of converting enzyme inhibition induced by enalapril on parasympathetic activity, we studied ten essential hypertensive patients, age range 38–58 years, WHO I–II. Parasympathetic evaluation was obtained by measuring the variation of heart period (VHP) during at least 1 minute of steady-state, regular respiration. VHP was derived from the difference between the mean of all maximum and the mean of all minimum heart periods. The higher the VHP, the higher the parasympathetic control of heart rate and vice versa. VHP was measured supine and with tilting (30°, 60°, 85°). Blood pressure was reduced after 1 month of enalapril treatment, while the heart rate did not change. VHP increased at the end of enalapril treatment compared with placebo: in the supine position it increased from 36±3.2 ms to 44±3.5 ms, p〈0.01. VHP was also increased by enalapril at 30° (p〈0.05) and 60° (p〈0.05), while no difference was observed at 85° between placebo and enalapril. A positive correlation was found between supine enalapril changes of VHP and those of systolic and diastolic BP. In conclusion, enalapril seems to increase parasympathetic cardiovascular control in essential hypertensive patients. This result might explain the lack of increase in heart rate that would be expected as a result of the vasodilating effect of enalapril.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Neurochemical research 19 (1994), S. 283-288 
    ISSN: 1573-6903
    Keywords: Lipid peroxidation ; rat brain ; scavengers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim of this study was to set up a simple procedure for assessing lipid peroxidation (L.P.) and testing the activity of antioxidant compounds. L. P. was determined in rat brain homogenates by measuring the endogenous and stimulated accumulation of malonaldehyde (MDA). MDA was assayed by an HPLC method. Homogenates spontaneously formed appreciable amounts of MDA. The addition of increasing concentrations of FeCl2 resulted in a linear accumulation of MDA, up to 16.6-fold at 50 μM. An organic form of iron (Fe-saccharate) was less active on MDA formation (11.4-fold increase at 100 μM). The addition of xanthine-xanthine oxidase resulted in only a 2.4-fold increase in MDA formation. Various antioxidant or chelating compounds effectively inhibited L.P., with IC50 between 0.1 μM (phenoxazine) and 4–50 μM (α-tocopherol). Their potencies depended on the iron concentration and time of preincubation with the homogenates. In conclusion, this is a simple and reliable procedure for studying L.P. and inhibiting agents, provided that the experimental conditions are carefully assessed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-689X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A general-purpose minicomputer has been adapted and interfaced for the averaging and analysis of clinical evoked potentials and for compressed spectral arrays (CSA) of the routine EEG. In the first 2 years of operation, over 1,000 routine clinical studies of visual evoked potentials (VEP) and brainstem auditory evoked potentials (BAEP) have been performed with it, as well as over 100 CSAs and a variety of special and research studies. The CSA modality gives comparative frequency-domain pictures of left and right hemisphere power. An attached graphics terminal gives a live cumulative display of the EP and CSA. In addition, the system has automated and comprehensive physician-interactive graphics analysis and report generation capabilities. The reports are finalized versions used in the patient's chart, minimizing clerical efforts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neural transmission 105 (1998), S. 627-633 
    ISSN: 1435-1463
    Keywords: Keywords: Nitric oxide ; nitrite ; nitrate ; human CSF ; HPLC analysis.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary. In order to evaluate the involvement of nitric oxide in neurologic disorders it is important to generate controlled values of its metabolites nitrite and nitrate in human cerebrospinal fluid (CSF). Samples of CSF obtained from 14 patients without neurologic diseases were analysed for nitrite and nitrate concentration by reverse phase chromatography with ultraviolet (UV) detection. For comparison, the levels of nitrite in the same samples were also measured by reverse phase chromatography coupled with electrochemical detection and those of nitrate by ion chromatography coupled with UV detection. A good correlation was found for the concentration values of both ions obtained with the two procedures. Then, 10.41 ± 0.47 ng/ml of nitrite and 2.92 ± 0.37 ng/ml of nitrate could be regarded as reliable values in control subjects. No correlation between age and levels of nitrite and nitrate was observed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Neurological sciences 16 (1995), S. 69-72 
    ISSN: 1590-3478
    Keywords: animal models ; generalized epilepsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Sommario I modelli animali di crisi epilettiche generalizzate sono attualmente soddisfacenti seppur migliorabili per quanto concernono le crisi generalizzate primarie a tipo piccolo male. Vi sono altresì modelli di crisi secondariamente generalizzate che permettono lo studio di alcuni dei meccanismi di base del processo epilettogenico e/o che possono servire per vagliare l'efficacia di potenziali nuovi farmaci. Per altre forme di crisi quali, ad esempio, gli attacchi amiotonici, non esistono modelli. In genere, i modelli di epilessia sono meno siddisfacenti dei modelli delle crisi epilettiche, soprattutto perché i primi non riproducono la cronicità della condizione umana. Le epilessie spontanee osservate nei gatti domestici meritano uno studio più attento in quanto riproducono una grande varietà delle epilessie tipiche dell'uomo. Tutto sommato la modellistica sia di crisi che di sindromi epilettiche è ad uno stato più avanzato di quella della più parte delle patologie neuropsichiatriche eccezion fatta per il morbo di Parkinson.
    Notes: Abstract The state of the art for models of generalized seizures in animals is satisfactory, but improvable for what concerns primary generalized seizures of Petit-Mal type. Other models of secondary generalized seizures are available allowing acceptable ways of studying some mechanisms of epileptogenesis, and/or screening potentials new AEDs. For other forms of seizures such as amyotonic fits, there are no models. By and large, models of epilepsy are lagging behind models of seizures as most of the former when reproduced in the laboratory are short lived. Spontaneously occurring epilepsies in cats should be studied more widely as they may provide a wide variety of epileptic conditions not dissimilar from the ones seen in humans. Overall, models of seizures and epilepsies are more advanced than the models of most neuropsychiatric conditions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...