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Latini A Ferreira GC Scussiato K Schuck PF Solano AF Dutra-Filho CS Vargas CR Wajner M 《Cellular and molecular neurobiology》2007,27(4):423-438
1. Glutaric acidemia type I (GA I) is a neurometabolic disorder caused by deficiency of glutaryl-CoA dehydrogenase, which
leads to tissue accumulation of predominantly glutaric acid (GA) and also 3-hydroxyglutaric acid to a lesser amount. Affected
patients usually present progressive cortical atrophy and acute striatal degeneration attributed to the toxic accumulating
metabolites.
2. In the present study, we determined a number of oxidative stress parameters, namely chemiluminescence, thiobarbituric acid-reactive
substances (TBA-RS), total antioxidant reactivity (TAR), glutathione (GSH) levels, and the activities of catalase and glutathione
peroxidase (GPx), in various tissues from rats chronically exposed to GA or to saline (controls). High GA concentrations,
similar to those found in glutaric aciduria type I, were induced in the brain by three daily subcutaneous injections of saline-buffered
GA (5 μmol/g body weight) to Wistar rats of 5–22 days of life. The parameters were assessed 12 h after the last GA administration
in different brain structures, skeletal muscle, heart, liver, erythrocytes, and plasma. The lipid peroxidation parameters
chemiluminescence and/or TBA-RS measurements were found significantly increased in midbrain, liver, and erythrocytes of GA-injected
rats. The activity of GPx was significantly reduced in midbrain and markedly increased in liver. TAR measurement was significantly
reduced in midbrain and liver. Furthermore, GSH levels were reduced in liver and heart.
We also investigated the acute in vivo effect of GA administration on the same oxidative stress parameters in cerebral structures and erythrocytes from 22-day-old
rats. We found that TBA-RS values were significantly increased in erythrocytes, TAR levels were markedly decreased in midbrain
and cerebellum, and GPx activity mildly reduced in the midbrain.
3. These data showing an imbalance between antioxidant defences and oxidative damage, particularly in midbrain, liver, and
erythrocytes from GA-injected rats, indicate that oxidative stress might be involved in GA toxicity and that the midbrain,
where the striatum is located, is the brain structure more susceptible to GA chronic and acute exposition. 相似文献
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《Endocrine practice》2023,29(7):581-588
IntroductionLevothyroxine (LT4) at doses that maintain the serum thyroid-stimulating hormone levels within the normal range constitutes the standard of care for the treatment of hypothyroidism. After a few months, this eliminates the signs and symptoms of overt hypothyroidism in the majority of patients, owing to the endogenous activation of thyroxine to triiodothyronine, the biologically active thyroid hormone. Still, a small percentage of the patients (10%-20%) exhibit residual symptoms, despite having normal serum thyroid-stimulating hormone levels. These symptoms include cognitive, mood, and metabolic deficits, with a significant impairment in psychological well-being and quality of life.ObjectiveTo provide a summary of progress in the approach of patients with hypothyroidism that exhibit residual symptoms despite treatment.MethodsWe reviewed the current literature and here we focused on the mechanisms leading to a deficiency of T3 in some LT4-treated patients, the role of residual thyroid tissue and the rationale for combination therapy with LT4 + liothyronine (LT3).ResultsA score of clinical trials comparing therapy with LT4 versus LT4 + LT3 concluded that both are safe and equally effective (neither is superior); however, these trials failed to recruit a sufficiently large number of patients with residual symptoms. New clinical trials that considered LT4-treated symptomatic patients revealed that such patients benefit from and prefer therapy containing LT4 + LT3; desiccated thyroid extract has also been used with similar results. A practical approach to patients with residual symptoms and on initiation of combination therapy with LT4 + LT3 is provided.ConclusionA recent joint statement of the American, British, and European Thyroid Associations recommends that a trial with combination therapy be offered to patients with hypothyroidism that do not fully benefit from therapy with LT4. 相似文献
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D. Glenn Kennedy W. John Blanchflower Paul B. Young W. Brian Davidson 《Biological trace element research》1992,35(2):153-166
The first development of an α-face-specific radioimmunoassay for vitamin B12 is described. Sheep, fed a cobalt-deficient diet, and immunized with a conjugate between Co-β carboxypropyl cobalamin and
keyhole limpet hemocyanin, were used to produce antisera. The antisera crossreacted with Co-β derivatives of vitamin B12, but did not crossreact with the α-face vitamin B12 analog cobinamide. The antisera were used to develop a sensitive and reproducible radioimmunoassay that was free from contamination
with the nonspecific vitamin B12 binding protein, R-protein. Both the radioimmunoassay and measurements of plasma concentrations of methylmalonic acid were
applied to the diagnosis of cobalt/vitamin B12 deficiency in sheep. The assay correlated well with a commercially available radioassay and did not falsely detect normal
vitamin B12 concentration in plasma samples containing elevated concentrations of methylmalonic acid. 相似文献
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Barry Wolf 《Biochemical genetics》1979,17(7-8):703-707
We have biochemically characterized several parameters of propionyl CoA carboxylase (PCC) activity in fibroblast extracts from PCC-deficient patients belonging to the two minor genetic complementation groups, pcc B and pcc BC. Comparison of PCCs from these groups with those of the two major complementation groups, pcc A and pcc C, has demonstrated that PCCs from both the pcc B and pcc BC groups closely resemble each other as well as PCC from the pcc C group. These results further support the hypothesis that the pcc B and pcc BC lines are interallelic with respect to pcc C and consequently that the structural mutations in the PCCs from these groups involve the same subunit. 相似文献
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Brandon H Cherry Anh Q Nguyen Roger A Hollrah Arthur G Williams Jr Besim Hoxha Albert H Olivencia-Yurvati Robert T Mallet 《Experimental biology and medicine (Maywood, N.J.)》2015,240(12):1774-1784
Cardiac electromechanical dysfunction may compromise recovery of patients who are initially resuscitated from cardiac arrest, and effective treatments remain elusive. Pyruvate, a natural intermediary metabolite, energy substrate, and antioxidant, has been found to protect the heart from ischemia-reperfusion injury. This study tested the hypothesis that pyruvate-enriched resuscitation restores hemodynamic, metabolic, and electrolyte homeostasis following cardiac arrest. Forty-two Yorkshire swine underwent pacing-induced ventricular fibrillation and, after 6 min pre-intervention arrest, 4 min precordial compressions followed by transthoracic countershocks. After defibrillation and recovery of spontaneous circulation, the pigs were monitored for another 4 h. Sodium pyruvate or NaCl were infused i.v. (0.1 mmol·kg−1·min−1) throughout precordial compressions and the first 60 min recovery. In 8 of the 24 NaCl-infused swine, the first countershock converted ventricular fibrillation to pulseless electrical activity unresponsive to subsequent countershocks, but only 1 of 18 pyruvate-treated swine developed pulseless electrical activity (relative risk 0.17; 95% confidence interval 0.13–0.22). Pyruvate treatment also lowered the dosage of vasoconstrictor phenylephrine required to maintain systemic arterial pressure at 15–60 min recovery, hastened clearance of excess glucose, elevated arterial bicarbonate, and raised arterial pH; these statistically significant effects persisted up to 3 h after sodium pyruvate infusion, while infusion-induced hypernatremia subsided. These results demonstrate that pyruvate-enriched resuscitation achieves electrocardiographic and hemodynamic stability in swine during the initial recovery from cardiac arrest. Such metabolically based treatment may offer an effective strategy to support cardiac electromechanical recovery immediately after cardiac arrest. 相似文献