RESUMEN
OBJECTIVES: The aim was to study the association between venous disorders and leg symptoms in the population based cross sectional Bonn Vein Study 1 (BVS1). METHODS: A total of 1,350 men and 1,722 women aged 18-79 years were enrolled into BVS1. Chronic venous insufficiency (CVI), varicose veins (VVs), and clinical classes (C-classes/CEAP [Clinical, Etiological, Anatomical, and Pathophysiological]) were determined by clinical and duplex investigation. Leg symptoms (heaviness, tightness, swelling, pain after standing or sitting, pain while walking, muscle cramps, itching, and restless legs) were assessed in a standardized interview. For 2,624 subjects (48.7% male) with complete information on venous disorders, relevant characteristics and information on at least one leg symptom, multivariate logistic regression analysis was performed. RESULTS: More women (929/63.0%) reported at least one leg symptom within the last 4 weeks than men (560/48.7%). Prevalence of reported symptoms increased with age (45.4% of the 18-29 year olds, 73.9% of the 70-79 year olds). Leg symptoms were more frequent in obese and underweight subjects. As confirmed by clinical and duplex examination 22.6% had VV and 15.8% had CVI. VV (OR: 1.4; CI: 1.1-1.7) and CVI (OR: 1.8; CI: 1.3-2.3) were significantly associated with reporting at least one leg symptom. In particular, there was a positive association of VV and CVI with itching, feeling of heaviness, tightness, swelling, and pain after standing or sitting. C2-C6 showed a statistically significant association with feeling of heaviness, tightness, swelling, and itching, while for pain on walking and muscle cramps this was shifted towards C classes C3-C6 and C3-C4, respectively. CONCLUSIONS: Venous disorders show significant associations with several leg symptoms. Itching, feeling of heaviness, or tightness seem to be more closely related than other symptoms. The associations between C classes and symptoms seem to be restricted to classes C2 or higher.
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Extremidad Inferior/irrigación sanguínea , Várices/epidemiología , Insuficiencia Venosa/epidemiología , Adolescente , Adulto , Anciano , Enfermedad Crónica , Comorbilidad , Estudios Transversales , Femenino , Alemania/epidemiología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Dimensión del Dolor , Prevalencia , Pronóstico , Factores de Riesgo , Factores de Tiempo , Ultrasonografía Doppler Dúplex , Várices/diagnóstico , Várices/fisiopatología , Insuficiencia Venosa/diagnóstico , Insuficiencia Venosa/fisiopatología , Adulto JovenRESUMEN
Tryptamine-4,5-dione (T-4,5-D) is formed as a result of oxidation of 5-hydroxytryptamine by superoxide (O(2)(-)(*), nitric oxide (NO*), and peroxynitrite (ONOO(-)). T-4,5-D rapidly inactivates tryptophan hydroxylase (TPH), derived from rat brain, probably as a result of covalent modification of active site cysteine residues. The activity of TPH exposed to T-4,5-D cannot be restored by anaerobic reduction with dithiothreitol (DTT) and ferrous iron (Fe(2+)) indicating that the inactivation is irreversible. 7-S-Glutathionyl-tryptamine-4,5-dione, formed by the rapid reaction between T-4,5-D and glutathione, also inhibits TPH but in this case the activity is restored by anaerobic reduction with DTT/Fe(2+). The results of this investigation may be relevant to the initial reversible and subsequent irreversible inactivation of TPH evoked by methamphetamine and 3,4-methylenedioxymethamphetamine.
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Estimulantes del Sistema Nervioso Central/toxicidad , Indolquinonas , Metanfetamina/toxicidad , Triptaminas/farmacología , Triptófano Hidroxilasa/efectos de los fármacos , Triptófano Hidroxilasa/metabolismo , Animales , Encéfalo/enzimología , Encéfalo/fisiología , Estimulantes del Sistema Nervioso Central/farmacología , Cromatografía Líquida de Alta Presión , Masculino , Metanfetamina/farmacología , Oxidantes , Oxidación-Reducción , Ratas , Ratas Sprague-Dawley , Triptaminas/químicaRESUMEN
The release and subsequent reuptake of 5-hydroxytryptamine (5-HT) and cytoplasmic superoxide (O2-*) generation have both been implicated as important factors associated with the degeneration of serotonergic neurons evoked by methamphetamine (MA) and cerebral ischemia-reperfusion (I-R). Such observations raise the possibility that tryptamine-4,5-dione (T-4,5-D), the major in vitro product of the O2-*-mediated oxidation of 5-HT, might be an endotoxicant that contributes to serotonergic neurodegeneration. When incubated with intact rat brain mitochondria, T-4,5-D (< or = 100 microM) uncouples respiration and inhibits state 3. Experiments with rat brain mitochondrial membrane preparations confirm that T-4,5-D evokes irreversible inhibition of NADH-coenzyme Q1 (CoQ1) reductase and cytochrome c oxidase (COX) apparently by covalently modifying key sulfhydryl (SH) residues at or close to the active sites of these respiratory enzyme complexes. Ascorbic acid blocks the inhibition of NADH-CoQ1 reductase by maintaining T-4,5-D predominantly as 4, 5-dihydroxytryptamine (4,5-DHT), thus preventing its reaction with SH residues. In contrast, ascorbic acid potentiates the irreversible inhibition of COX by T-4,5-D. This may be because the T-4,5-D-4, 5-DHT couple redox cycles in the presence of excess ascorbate and molecular oxygen to cogenerate O2-* and H2O2 that together react with trace levels of iron to form an oxo-iron complex that selectively damages COX. Thus, T-4,5-D might be an endotoxicant that, dependent on intraneuronal conditions, mediates irreversible damage to mitochondrial respiratory enzyme complexes and contributes to the serotonergic neurodegeneration evoked by MA and I-R.
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Endotoxinas/metabolismo , Indolquinonas , Mitocondrias/efectos de los fármacos , Enfermedades Neurodegenerativas/metabolismo , Serotonina/metabolismo , Superóxidos/metabolismo , Triptaminas/metabolismo , Triptaminas/toxicidad , Animales , Ácido Ascórbico/farmacología , Química Encefálica/efectos de los fármacos , Complejo IV de Transporte de Electrones/antagonistas & inhibidores , Técnicas In Vitro , Masculino , Oxidación-Reducción , Consumo de Oxígeno/efectos de los fármacos , Ratas , Ratas Sprague-DawleyRESUMEN
A novel approach for assessing the peroxidative chain initiation potency of lipid hydroperoxides has been developed, which involves use of 14C-labeled cholesterol (Ch) as a "reporter" lipid. Unilamellar liposomes containing 1-palmitoyl-2-oleoyl-phosphatidylcholine, [14C]Ch, and 3beta-hydroxy-5alpha-cholest-6-ene-5-hydroperoxide (5alpha-OOH) or 3beta-hydroxycholest-5-ene-7alpha-hydroperoxide (7alpha-OOH) [100:75:5, mol/mol] were used as a test system. Liposomes incubated in the presence of ascorbate and a lipophilic iron complex were analyzed for radiolabeled oxidation products/intermediates (ChOX) by means of silica gel high-performance thin layer chromatography with phosphorimaging detection. The following ChOX were detected and quantified: 7alpha-OOH, 7beta-OOH, 7alpha-OH, 7beta-OH, and 5, 6-epoxide. Total ChOX yield increased in essentially the same time- and [iron]-dependent fashion for initiating 5alpha-OOH and 7alpha-OOH. The initial rate of [14C]7alphabeta-OH formation was greatly diminished when GSH and ebselen (a selenoperoxidase mimetic) were present, consistent with the attenuation of one-electron peroxide turnover. [14C]Ch-labeled L1210 cells also accumulated ChOX when incubated with 5alpha-OOH-containing liposomes. The rate of accumulation was substantially greater for Se-deficient than Se-sufficient cells, indicating that peroxide-induced chain reactions were modulated by selenoperoxidase action. These results illustrate the advantages of the new approach for highly sensitive in situ monitoring of cellular peroxidative damage.
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Colesterol/metabolismo , Peróxidos Lipídicos/metabolismo , Animales , Azoles/metabolismo , Técnicas Biosensibles , Cromatografía Líquida de Alta Presión/métodos , Transporte de Electrón , Radicales Libres , Hierro/metabolismo , Isoindoles , Leucemia L1210/metabolismo , Liposomas , Ratones , Compuestos de Organoselenio/metabolismo , Células Tumorales CultivadasRESUMEN
Authors present methods of treatments at the Clinic of Urology Medical University of Lódz in patients after gynecological tumors with ureteral strictures caused by radiotherapy or progression of cancer.
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Neoplasias de los Genitales Femeninos/radioterapia , Obstrucción Ureteral/etiología , Obstrucción Ureteral/cirugía , Femenino , Neoplasias de los Genitales Femeninos/diagnóstico por imagen , Humanos , Radioterapia/efectos adversos , Tomografía Computarizada por Rayos XRESUMEN
We studied 42 infertile men, who had been surgically treated with modified Palomo method, with intraoperative phlebography of single or multiple testicular veins. We evaluated the efficacy of the performed procedure as well as the presence of other ways of recoil outflow and the connections between the venous vessels of the right testis. In 42 cases surgically treated men with varicocele only in 4 cases the varicocele have been observed additionally on the right side. We are of the opinion that the intraoperative phlebography allows us to performed the proper and the most effective method of the operation of varicocele.
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Cuidados Intraoperatorios , Varicocele/diagnóstico , Varicocele/cirugía , Adulto , Humanos , Masculino , Flebografía/métodos , Testículo/irrigación sanguínea , Testículo/diagnóstico por imagenRESUMEN
Many new lines of evidence implicate both superoxide anion radical (O2*-) and biogenic amine neurotransmitters in the pathological mechanisms that underlie neuronal damage caused by methamphetamine (MA), glutamate-mediated oxidative toxicity, ischemia-reperfusion, and other neurodegenerative brain disorders. In this investigation the oxidation of 5-hydroxytryptamine (5-HT, serotonin) by an O2*--generating system (xanthine/xanthine oxidase) in buffered aqueous solution at pH 7.4 has been studied. The major product of the O2*--mediated oxidation of 5-HT is tryptamine-4,5-dione (T-4, 5-D). However, O2*- and H2O2, cogenerated by the xanthine oxidase-mediated oxidation of xanthine to uric acid, together react with trace levels of iron that contaminate buffer constituents to give a chemically ill-defined oxo-iron species. This species mediates the oxidation of 5-HT to a C(4)-centered carbocation intermediate that reacts with 5-HT to give 5,5'-dihydroxy-4, 4'-bitryptamine (4,4'-D) and with uric acid to give 9-[3-(2-aminoethyl)-5-hydroxy-1H-indol-4-yl]-2,6,8-triketo-1H,3H, 7H-purine (7) as the major products. These products differ from those formed in the HO*-mediated oxidation of 5-HT under similar conditions. When the reaction is carried out in the presence of the intraneuronal nucleophile glutathione (GSH), T-4,5-D is scavenged to give 7-(S-glutathionyl)tryptamine-4,5-dione, whereas the putative carbocation intermediate is scavenged to give 4-(S-glutathionyl)-5-hydroxytryptamine. T-4,5-D also reacts with the sulfhydryl residues of a model protein, alcohol dehydrogenase, and inhibits its activity. Previous investigators have proposed that T-4, 5-D is a serotonergic neurotoxin. This raises the possibility that T-4,5-D and perhaps other putative intraneuronal metabolites formed by the O2*-/H2O2/oxo-iron-mediated oxidations of 5-HT might be endotoxins that contribute to neurodegeneration in brain regions innervated by serotonergic neurons caused by MA, ischemia-reperfusion, and other neurodegenerative brain disorders.
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Encefalopatías/etiología , Indolquinonas , Enfermedades Neurodegenerativas/etiología , Serotonina/metabolismo , Superóxidos/metabolismo , Antioxidantes/farmacología , Depuradores de Radicales Libres/farmacología , Radicales Libres , Glutatión/farmacología , Humanos , Quelantes del Hierro/farmacología , Oxidación-Reducción , Unión Proteica , Triptaminas/metabolismoRESUMEN
Oxygen radicals have been implicated in the neurodegenerative and other neurobiological effects evoked by methamphetamine (MA) in the brain. It has been reported that shortly after a single large subcutaneous dose of MA to the rat, the serotonergic neurotoxin 5,6-dihydroxytryptamine (5,6-DHT) is formed in the cortex and hippocampus. This somewhat controversial finding suggests that MA potentiates formation of the hydroxyl radical (HO.) that oxidizes 5-hydroxytryptamine (5-HT) to 5,6-DHT, which, in turn, mediates the degeneration of serotonergic terminals. A major and more stable product of the in vitro HO.-mediated oxidation of 5-HT is 5-hydroxy-3-ethylamino-2-oxindole (5-HEO). In this investigation, a method based on HPLC with electrochemical detection (HPLC-EC) has been developed that permits measurement of very low levels of 5-HEO in rat brain tissue in the presence of biogenic amine neurotransmitters/metabolites. After intracerebroventricular administration into rat brain, 5-HEO is transformed into a single major, but unknown, metabolite that can be detected by HPLC-EC. One hour after administration of MA (100 mg/kg s.c.) to the rat, massive decrements of 5-HT were observed in all regions of the brain examined (cortex, hippocampus, medulla and pons, midbrain, and striatum). However, 5-HEO, its unidentified metabolite, or 5,6-DHT were not detected as in vivo metabolites of 5-HT. MA administration, in particular to rats pretreated with pargyline, resulted in the formation of low levels of N-acetyl-5-hydroxytryptamine (NAc-5-HT) in all brain regions examined. These results suggest that MA does not potentiate the HO.-mediated oxidation of 5-HT. Furthermore, the rapid MA-induced decrease of 5-HT might not only be related to oxidative deactivation of tryptophan hydroxylase, as demonstrated by other investigators, but also to the inhibition of tetrahydrobiopterin biosynthesis by NAc-5-HT. The massive decrements of 5-HT evoked by MA are accompanied by small or no corresponding increases in 5-hydroxyindole-3-acetic acid (5-HIAA) levels. This is due, in part, to the relatively rapid clearance of 5-HIAA from the brain and monoamine oxidase (MAO) inhibition by MA. However, the loss of 5-HT without corresponding increases in its metabolites point to other mechanisms that might deplete the neurotransmitter, such as oxidation by superoxide radical anion (O2.-), a reaction that in vitro does not generate 5-HEO or 5,6-DHT but rather another putative neurotoxin, tryptamine-4,5-dione. One hour after administration, MA evokes large depletions of norepinephrine (NE) throughout the brain but somewhat smaller decrements of dopamine (DA) that are restricted to the nigrostriatal pathway. Furthermore, MA evokes a major shift in the metabolism of both NE and DA from the pathway mediated by MAO to that mediated by catechol-O-methyltransferase. The profound and widespread effects of MA on the noradrenergic system, but more anatomically localized influence on the dopaminergic system, suggests that NE in addition to DA, or unusual metabolites of these neurotransmitters, might play roles in the neurodegenerative effects evoked by this drug.
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Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Dopaminérgicos/farmacología , Metanfetamina/farmacología , Animales , Dopaminérgicos/administración & dosificación , Relación Dosis-Respuesta a Droga , Radical Hidroxilo/metabolismo , Indoles/metabolismo , Inyecciones Intraventriculares , Masculino , Metanfetamina/administración & dosificación , Oxidación-Reducción/efectos de los fármacos , Oxindoles , Ratas , Ratas Sprague-Dawley , Serotonina/análogos & derivados , Serotonina/metabolismo , Serotonina/farmacocinética , Factores de TiempoRESUMEN
Ethanol is metabolized in the brain by catalase/H2O2 to yield acetaldehyde and by an ethanol-inducible form of cytochrome P450 (P450 IIE1) in a reaction that yields oxygen radicals. Within the cytoplasm of serotonergic axon terminals these metabolic pathways together provide conditions for the endogenous synthesis of 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline (1), by reaction of acetaldehyde with unbound 5-hydroxytryptamine (5-HT), and for the oxygen radical-mediated oxidation of this alkaloid. The major initial product of the hydroxyl radical (HO.)-mediated oxidation of 1 in the presence of free glutathione (GSH), a constituent of nerve terminals and axons, is 8-S-glutathionyl-1-methyl-1,2,3,4-tetrahydro-beta-carboline-5,6-dione (6). When administered into the brains of mice, 6 is a potent toxin (LD50 = 2.9 microg) and evokes episodes of hyperactivity and tremor. Compound 6 binds at the GABA(B) receptor and evokes elevated release and turnover of several neurotransmitters. Furthermore, the GABA(B) receptor antagonist phaclofen attenuates the behavioral response caused by intracerebral administration of 6. These observations suggest that 6 might be an inverse agonist at the GABA(B) receptor site. Accordingly, it is speculated that ethanol drinking might potentiate formation of 6 that contributes to elevated release of several neurotransmitters including dopamine (DA) and endogenous opioids in regions of the brain innervated by serotonergic axon terminals. Subsequent interactions of DA and opioids with their receptors might be related to the initial development of dependence on ethanol. Redox cycling of 6 (and of several putative secondary metabolites) in the presence of intraneuronal antioxidants and molecular oxygen to produce elevated fluxes of cytotoxic reduced oxygen species might contribute to the degeneration of serotonergic pathways. Low levels of 5-HT in certain brain regions of the rat predisposes these animals to drink or augments drinking. Accordingly, 6, formed as a result of ethanol metabolism in the cytoplasm of certain serotonergic axon terminals, might contribute to the initial development of dependence on ethanol, by mediating DA and opioid release, and long-term preference and addiction to the fluid as a result of the progressive degeneration of these neurons.
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Alcoholismo/complicaciones , Carbolinas/metabolismo , Etanol/metabolismo , Trastornos Relacionados con Sustancias/etiología , Animales , Baclofeno/análogos & derivados , Baclofeno/farmacología , Conducta Animal/efectos de los fármacos , Encefalopatías/inducido químicamente , Radical Hidroxilo , Masculino , Ratones , Ratones Endogámicos ICR , Neurotransmisores/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de GABA-B/efectos de los fármacosRESUMEN
In the event that methamphetamine evokes HO. formation within serotonergic axon terminals, the resultant oxidation of 5-HT would be expected to generate not only 5,6-DHT but also T-4,5-D, 7-S-Glu-T-4,5-D, 6, 8, and 7,7'-D (figure 1), at least three of which (T-4,5-D, 7-S-Glu-T-4,5-D, and 6) are lethal in mouse brain. Furthermore, several intermediates/products formed in the in vitro oxidation of 5-HT by HO. are readily autoxidized (4,5-DHT, 5,6-DHT, 5, 7, and 9) or redox cycled (T-4,5-D, 6, 8, 7,7'-D, 7-S-Glu-T-4,5-D) in reactions that would be expected to yield O2-. and/or H2O2 as byproducts. These byproducts, in the presence of trace levels of transition metal ion catalysts, would be readily converted into HO. (Walling 1975; Halliwell and Gutteridge 1984). Together these putative aberrant oxidative metabolites of 5-HT and HO.-forming reactions might contribute to the degeneration of serotonergic nerve terminals. Similarly, the methamphetamine-induced intraneuronal formation of HO. in dopaminergic terminals might be expected to generate not only 6-OHDA (and 2-OHDA and 5-OHDA, figure 3) but also 5,-S-CyS-DA and 5-S-Glu-DA, precursors of DHBT 17 and other more complex dihydrobenzothiazines (figure 4). DHBTs 17 to 19 are lethal in mouse brain, although at this time the biochemical/chemical mechanisms underlying this toxicity and specific neuronal systems affected are unknown. However, 5-S-CyS-DA and 17 to 19 are much more easily oxidized than DA, and the latter DHBTs appear to be capable of redox cycling reactions (Zhang and Dryhurst 1994). Thus, the HO.-mediated oxidation of DA in dopaminergic nerve terminals induced by methamphetamine might be expected to generate aberrant oxidative metabolites that (as a result of autoxidation and redox cycling reactions) potentiate formation of O2-. and/or H2O2, and then HO. and neuronal damage. A number of lines of evidence, discussed previously, suggest that aberrant metabolite(s) of DA (other than or in addition to 6-OHDA) might contribute to the methamphetamine-induced degeneration of not only dopaminergic terminals but also serotonergic terminals. Similarly, aberrant metabolite(s) of 5-HT (other than or in addition to 5,6-DHT) might be involved in the degeneration of serotonergic and dopaminergic terminals and a subpopulation of cell bodies in the somatosensory cortex. Experimental evidence indicates that some of the neurodegenerative effects evoked by methamphetamine are mediated by NMDA and GABA receptors. Thus, it will be of considerable interest to investigate the neurotoxicity of putative aberrant oxidative metabolites of 5-HT (figures 1 and 2) and DA (figures 4 and 5) towards serotonergic, dopaminergic, and other neuronal systems and their interactions with NMDA, GABA, and other brain receptors. A central question relates to mechanisms by which methamphetamine might evoke the intraneuronal formation of oxygen radicals that appear to play important roles in the overall neurodegenerative processes evoked by this drug (DeVito and Wagner 1989; Cadet et al. 1994). Once putative oxidative metabolites of 5-HT such as T-4,5-D, 7-S-Glu-T-4,5-D, 5,6-DHT, 6, 8, and 7,7'-D (figure 1) are formed intraneuronally, autoxidation/redox cycling reactions should, in principle, be capable of generating O2-. and/or H2O2, the precursors of HO.. Similarly, intraneuronal formation of 6-OHDA, 5-S-CyS-DA, and DHBTs 17 to 19 and 22 would also be expected to potentiate elevated fluxes of O2-., H2O2, and HO. as a result of the facile autoxidation/redox cycling reactions of these putative aberrant metabolites. The presence of very low concentrations of 5-S-CyS-DA in DA-rich regions of human and other mammalian brains suggest that autoxidation (Rosengren et al. 1985; Fornstedt et al. 1986, 1989, 1990) or perhaps some other form of DA oxidation is a normal reaction in vivo. Furthermore, available evidence suggests that it is cytoplasmic DA that is oxidized to give 5-S-CyS-DA (Fornstedt et al. 1989; Fornstedt and
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Encéfalo/efectos de los fármacos , Metanfetamina/toxicidad , Animales , Encéfalo/metabolismo , Dopamina/metabolismo , Humanos , Ratones , Oxidación-Reducción , Serotonina/metabolismoRESUMEN
A very early event in the pathogenesis of idiopathic Parkinson's disease (PD) has been proposed to be an elevated translocation of L-cysteine (CySH) and/or glutathione (GSH) into pigmented dopaminergic cell bodies in the substantia nigra (SN) in which cytoplasmic dopamine (DA) is normally autoxidized to DA-o-quinone as the first step in a reaction leading to black neuromelanin polymer. Such an elevated influx of CySH and GSH would be expected to initially result in formation of 5-S-cysteinyldopamine (5-S-CyS-DA) and 5-S-glutathionyldopamine (5-S-Glu-DA), respectively, and might account for the massive irreversible loss of GSH and progressive depigmentation of SN cells that occurs in the Parkinsonian brain. However, 5-S-Glu-DA has not been detected in the Parkinsonian brain. Furthermore, although the 5-S-CyS-DA/DA and 5-S-CyS-DA/homovanillic acid concentration ratios increase significantly in the SN and cerebrospinal fluid, respectively, of PD patients, the absolute concentrations of 5-S-CyS-DA are extremely low and similar to those measured in age-matched control patients. One explanation for these observations is that 5-S-CyS-DA might be intraneuronally oxidized to more complex cysteinyldopamines and a number of dihydrobenzothiazines (DHBTs) and benzothiazines (BTs). Similarly, 5-S-Glu-DA might be intraneuronally oxidized to more complex glutathionyldopamines. In this investigation, however, it is demonstrated that 5-S-Glu-DA is rapidly metabolized in rat brain to 5-S-CyS-DA and 5-S-(N-acetylcysteinyl) dopamine (5) in reactions mediated by gamma-glutamyl transpeptidase (gamma-GT) and cysteine conjugate N-acetyltransferase. Similarly, 5-S-CyS-DA is metabolized to 5 in rat brain although more slowly than 5-S-Glu-DA. These reactions occur most rapidly in the midbrain, a region that contains the SN. Furthermore, 5, 2-S-(N-acetylcysteinyl)dopamine (6) and 2,5-di-S-(N-acetylcysteinyl)-dopamine (9) are toxic when administered into mouse brain having LD50 values of 14, 25, and 42 micrograms, respectively, and evoke a profound hyperactivity syndrome. These results suggest that the failure to detect 5-S-Glu-DA and the presence of only very low levels of 5-S-CyS-DA in Parkinsonian SN tissue and CSF might be related to both their intraneuronal oxidation and extraneuronal metabolism to N-acetylcysteinyl conjugates of DA. Furthermore, the toxic properties and neurobehavioral responses evoked by 5, 6, and 9 raise the possibility that these N-acetylcysteinyl conjugates of DA, in addition to certain cysteinyldopamines, DHBTs and BTs, might include endotoxins that contribute to SN cell death and other neuronal damage that occurs in PD. Methods are described for the synthesis of several N-acetylcysteinyl conjugates of DA, and their redox behaviors have been studied using cyclic voltammetry.
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Acetilcisteína/metabolismo , Acetilcisteína/toxicidad , Encéfalo/efectos de los fármacos , Cisteinildopa/biosíntesis , Cisteinildopa/toxicidad , Dopamina/metabolismo , Dopamina/toxicidad , Enfermedad de Parkinson/etiología , Animales , Cisteinildopa/metabolismo , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos ICR , Oxidación-Reducción , Ratas , Ratas Sprague-DawleyRESUMEN
When incubated with a hydroxyl radical (HO.)-generating system (ascorbic acid/Fe(2+)-EDTA/O2/H2O2), 5-hydroxytryptamine (5-HT; serotonin) is rapidly oxidized initially to a mixture of 2,5-, 4,5-, and 5,6-dihydroxytryptamine (DHT). The major reaction product is 2,5-DHT, which at physiological pH exists as its keto tautomer, 5-hydroxy-3-ethylamino-2-oxindole (5-HEO). Rapid autoxidation of 4,5-DHT gives tryptamine-4,5-dione (T-4,5-D), which reacts with the C(3)-centered carbanion of 5-HEO to give 3,3'-bis(2-aminoethyl)-5-hydroxy-[3,7'-bi-1H-indole]-2,4',5'- 3H-trione (7). The latter slowly cyclizes to 3'-(2-aminoethyl)-1',6',7',8'-tetrahydro-5-hydroxy-spiro[3H-indole-3,9'- [9H]pyrrolo[2,3-f]quinoline]-2,4',5' (1H)-trione (9). A minor amount of T-4,5-D dimerizes to give 7,7'-bi-(5-hydroxytryptamine-4-one) (7,7'-D). In the presence of GSH, the reaction of T-4,5-D with 5-HEO is diverted and, in the presence of sufficient concentrations of this tripeptide, completely blocked. This is because GSH preferentially reacts with T-4,5-D to give 7-S-glutathionyltryptamine-4,5-dione (11). The results of this investigation suggest that 5,6-DHT, 5-HEO, 7, and 9 are products unique to the HO.-mediated oxidation of 5-HT. Thus, the observation of other investigators that 5,6-DHT is formed in the brains of rats following a large dose of methamphetamine (MA) suggests that this drug might evoke HO. formation. However, the present in vitro study indicates that 5,6-DHT is a rather minor, unstable product of the HO.-mediated oxidation of 5-HT and suggests that detection of 5-HEO, 7/9, and 11 in rat brain following MA administration could provide additional support for HO. formation. Furthermore, one or more of the intermediates and major products of oxidation of 5-HT by HO. might, in addition to 5,6-DHT, contribute to the MA-induced degeneration of serotonergic neurons.
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Radical Hidroxilo/química , Metanfetamina/toxicidad , Neurotoxinas , Serotonina/química , Cromatografía Líquida de Alta Presión , Electroquímica , Neurotoxinas/química , Oxidación-Reducción , Espectrofotometría UltravioletaRESUMEN
In the mouse uterus, lactoferrin is a major estrogen-inducible uterine secretory protein, and its expression correlates directly with the period of peak epithelial cell proliferation. In this study, we examine the expression of lactoferrin mRNA and protein in human endometrium, endometrial hyperplasias, and adenocarcinomas using immunohistochemistry, Western immunoblotting, and Northern and in situ RNA hybridization techniques. Our results reveal that lactoferrin is expressed in normal cycling endometrium by a restricted number of glandular epithelial cells located deep in the zona basalis. Two thirds (8 of 12) of the endometrial adenocarcinomas examined overexpress lactoferrin. This tumor-associated increase in lactoferrin expression includes an elevation in the mRNA and protein of individual cells and an increase in the number of cells expressing the protein. In comparison, only 1 of the 10 endometrial hyperplasia specimens examined demonstrates an increase in lactoferrin. We also observe distinct cytoplasmic and nuclear immunostaining patterns under different fixation conditions in both normal and malignant epithelial cells, similar to those previously reported in the mouse reproductive tract. Serial sections of malignant specimens show a good correlation between the localization of lactoferrin mRNA and protein in individual epithelial cells by in situ RNA hybridization and immunohistochemistry. Although the degree of lactoferrin expression in the adenocarcinomas did not correlate with the tumor stage, grade, or depth of invasion in these 12 patients, there was a striking inverse correlation between the presence of progesterone receptors and lactoferrin in all 8 lactoferrin-positive adenocarcinomas. In summary, lactoferrin is expressed in a region of normal endometrium known as the zona basalis which is not shed with menstruation and is frequently overexpressed by progesterone receptor-negative cells in endometrial adenocarcinomas.
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Transformación Celular Neoplásica/genética , Neoplasias Endometriales/patología , Endometrio/metabolismo , Endometrio/patología , Lactoferrina/biosíntesis , Lactoferrina/genética , ARN Mensajero/análisis , Adenocarcinoma/química , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Adulto , Anciano , Northern Blotting , Hiperplasia Endometrial/metabolismo , Hiperplasia Endometrial/patología , Neoplasias Endometriales/química , Neoplasias Endometriales/metabolismo , Endometrio/química , Femenino , Humanos , Inmunohistoquímica , Hibridación in Situ , Antígeno Ki-67 , Persona de Mediana Edad , Proteínas de Neoplasias/análisis , Compuestos de Nitrosourea/análisis , Proteínas Nucleares/análisis , Fenotipo , ARN Mensajero/genética , Receptor ErbB-2/análisis , Receptores de Estrógenos/análisis , Receptores de Progesterona/análisis , Neoplasias Uterinas/química , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patologíaRESUMEN
Recent reports of fatigue failures of polyethylene tibial and patellar components have led to investigation of the role of design and material properties in these failures. Earlier investigations, concluding that high contact stress designs suffered greater damage in service, could not account for some of the fatigue failures. The current study hypothesizes that this failure is related to variations in the material properties of the polyethylene due to incomplete consolidation of the powder during manufacture, resulting in fusion defects. Retrieved polyethylene components and samples of polyethylene stock were examined to gain insight into the relationship between fusion defects, component failure, material forming processes, and powder grade. Statistically significant correlations (p < 0.05) were observed between the extent of defects and cracking, delamination, total wear damage, and duration in vivo. These correlations indicate that components manufactured from material with fusion defects may be less resistant to fatigue than components formed of fully consolidated material.
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Prótesis de la Rodilla , Polietilenos , Acetábulo , Cristalografía , Humanos , Prótesis de la Rodilla/estadística & datos numéricos , Ensayo de Materiales/instrumentación , Ensayo de Materiales/métodos , Ensayo de Materiales/estadística & datos numéricos , Polietilenos/química , Diseño de Prótesis/estadística & datos numéricos , Falla de Prótesis , Estrés Mecánico , Propiedades de Superficie , TibiaRESUMEN
Tryptamine-4,5-dione (Compound 1) is an in vitro oxidation product of 5-hydroxytryptamine (5-HT). Recent evidence has suggested that aberrant oxidations of 5-HT occur in the central nervous system of individuals with Alzheimer's disease (AD). In the event that Compound 1 is formed as a result of oxidation of 5-HT within serotonergic nerve terminals or axons, it would be expected to be rapidly conjugated by intraneuronal glutathione (GSH) to give 7-S-glutathionyl-tryptamine-4,5-dione (Compound 2). When injected into the brains of laboratory mice, Compound 2 was lethal (LD50 = 21 micrograms) and evoked hyperactivity for the first 30 min following drug administration. Particularly during this hyperactive phase Compound 2 caused a statistically significant decrease in whole brain levels of norepinephrine and 5-HT. Levels of dopamine were also decreased while whole brain concentrations of its metabolites, 3,4-dihydroxyphenylacetic acid and homovanillic acid, were increased significantly. In the presence of GSH, NADPH and ascorbic acid, Compound 2 redox cycled in reactions that catalyzed the oxidation of these cellular reductants by molecular oxygen and formed H2O2 as a byproduct. Compound 2 also reacted with molar excesses of GSH to form more structurally complex glutathionyl conjugates. Several of these conjugates have been isolated and their structures determined using spectroscopic methods. It is conceivable that one or more of these conjugates might serve as analytical markers in a search for evidence in support of the hypothesis that aberrant oxidations of 5-HT occur in the Alzheimer brain. The redox cycling properties of Compound 2 and its facile reactions with cellular nucleophiles such as GSH may represent mechanisms that contribute to the toxicity of this drug.
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Química Encefálica , Glutatión/análogos & derivados , Serotonina/metabolismo , Triptaminas/metabolismo , Acetilcolina/metabolismo , Enfermedad de Alzheimer/metabolismo , Animales , Dopamina/metabolismo , Glutatión/síntesis química , Glutatión/metabolismo , Glutatión/farmacología , Masculino , Ratones , Norepinefrina/metabolismo , Oxidación-Reducción , Consumo de Oxígeno/efectos de los fármacos , Serotonina/análogos & derivados , Triptaminas/síntesis química , Triptaminas/farmacologíaRESUMEN
The goal of this study was to examine the early retrievals of hydroxyapatite-(HA) coated hip prostheses to assess evidence of osteoconductivity, resorption of HA, and the integrity of the HA/implant bond. Six retrieved HA-coated hip prostheses (3 femoral hip stems, 3 acetabular cups) were analyzed for the amount of bone ongrowth or ingrowth of the HA-coated surface and the extent to which the coating was still present after in vivo service. The examination of these six HA-coated prostheses indicates that HA appeared to be osteoconductive. There was evidence of debonding of HA from the smooth-surfaced femoral prosthesis, although that may have been a result of the extraction process. The five plasma-spray surfaced, HA-coated prostheses showed evidence of considerable loss of the HA coating at the time of receipt in the authors' laboratory, although it is was not possible to determine the cause of the loss of coating.
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Durapatita , Prótesis de Cadera , Durapatita/farmacología , Prótesis de Cadera/métodos , Humanos , Oseointegración , Diseño de PrótesisRESUMEN
Previous investigators have detected unknown oxidized forms of 5-hydroxytryptamine (5-HT) in the CSF of Alzheimer's disease (AD) patients. Furthermore, an unidentified autoxidation product of this neurotransmitter is an inhibitor of acetylcholinesterase (AChE), an enzyme compromised in the Alzheimer brain. In this study it is demonstrated that the major product of autoxidation of 5-HT is 5,5'-dihydroxy-4,4'-bitryptamine (DHBT). Central administration of DHBT to mice at a dose of 40 micrograms (free base) evokes profound behavioral responses, which persist until the animals die (approximately 24 h). One hour after central administration of DHBT, the levels of norepinephrine, dopamine, 5-HT, and acetylcholine and their metabolites in whole brain are greatly elevated. Disturbances to the catecholaminergic and serotonergic systems were still evident shortly before the death of animals. DHBT is also shown to be a noncompetitive inhibitor of AChE in vitro. These observations suggest that if DHBT is formed as an aberrant metabolite of 5-HT in the human brain, it could potentially be neurotoxic and contribute to the neuronal degeneration and other neurochemical and neurobiochemical changes associated with AD or perhaps other neurodegenerative diseases.
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Neurotoxinas/biosíntesis , Serotonina/metabolismo , Triptaminas/biosíntesis , Animales , Conducta Animal , Encéfalo/metabolismo , Inhibidores de la Colinesterasa/farmacología , Masculino , Ratones , Neurotransmisores/metabolismo , Oxidación-Reducción , Triptaminas/farmacología , Triptaminas/toxicidadRESUMEN
Lactoferrin (LTF), an iron-binding glycoprotein present in most exocrine secretions and in the secondary granules of polymorphonuclear leucocytes (PMN), is regulated by estrogen in the mouse reproductive tract. We investigated the expression of LTF mRNA and protein during the natural estrous cycle to increase our understanding of how this uterine secretory protein is regulated under physiological conditions. There was a positive correlation between LTF mRNA expression in the genital tract and serum estradiol (E2) concentrations. When E2 peaked in proestrus, LTF mRNA and protein were expressed in the uterus; however, during metestrus, when both E2 and progesterone levels were high, LTF mRNA was expressed, while LTF protein was decreasing. LTF protein expression may be hindered by progesterone or some other local factor in the endometrial epithelium after ovulation. Immunohistochemistry demonstrated two distinct staining patterns for LTF in the vaginal and endometrial epithelium. In one staining pattern, the colorimetric reaction was noted over the cytoplasm, and in the other, the nuclear region stained more intensely. This suggests the possibility that in addition to its known role as a secretory protein, LTF may be transported to the nucleus, serving an autocrine role. Our results also indicated that LTF protein is a useful marker for tracking PMN. Nonproliferating epithelial cells in the vagina and endometrium may synthesize chemotactic and/or adhesion molecules for PMN.