Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.9.3.1 (cytochrome oxidase)
 8,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report the case histories of two 6-month-old girls, both with young, nonconsanguineous parents, referred to us for suspected blindness. In both cases, Leber's congenital amaurosis was diagnosed. Due to persistently high lactic acid levels in blood, muscle biopsies were taken. Analysis of biopsies revealed that both patients had low levels of complex IV of the mitochondrial respiratory chain; one patient additionally had low levels of complex III. Microscopic and ultrastructural alterations of muscle, typically observed in mitochondrial disorders, were observed only in the second patient. These observations raise the possibility that at least some cases of Leber's congenital amaurosis may be due to alterations in the mitochondrial respiratory chain.
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PMID:Leber's congenital amaurosis associated with mitochondrial dysfunction. 888 86

To evaluate selective cerebral perfusion (SCP) for brain protection, the redox state of cytochrome oxidase (Cyt. aa3) in brain tissue were studied in 27 patients with thoracic aortic repair. The redox state of Cyt. aa3 was monitored by near infrared spectroscopy (NIRS) (OM-110, Shimazu). There were no significant changes in the Cyt. aa3 redox state in 13 (Group I), the oxidation state of Cyt. aa3 decreased then recovered to control levels in 12 (Group II), and the oxidation state decreased but did not recover in 2 patients (Group III). Postoperative cerebral damage was observed in 5 patients; blindness occurred in one patient in Group I (8.3%), 2 patients developed hemiplegia in Group II (15.4%), and the 2 patients in Group III failed to reawaken (100%). The incidence of cerebral damage was significantly higher in Group III than in Groups I and II (p < 0.05). We conclude that monitoring the redox state of Cyt. aa3 using NIRS is useful in predicting postoperative cerebral damage. However, it is necessary to increase the number of measurement sites since NIRS can reflect the state in only a small area of the brain.
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PMID:[Cerebral cytochrome oxidase monitoring by near infrared spectroscopy during selective cerebral perfusion]. 925 33

Methanol intoxication produces toxic injury to the retina and optic nerve, resulting in blindness. The toxic metabolite in methanol intoxication is formic acid, a mitochondrial toxin known to inhibit the essential mitochondrial enzyme, cytochrome oxidase. Photobiomodulation by red to near-IR radiation has been demonstrated to enhance mitochondrial activity and promote cell survival in vitro by stimulation of cytochrome oxidase activity. The present studies were undertaken to test the hypothesis that exposure to monochromatic red radiation from light-emitting diode (LED) arrays would protect the retina against the toxic actions of methanol-derived formic acid in a rodent model of methanol toxicity. Using the electroretinogram as a sensitive indicator of retinal function, we demonstrated that three brief (2 min, 24 s) 670-nm LED treatments (4 J/cm(2)), delivered at 5, 25, and 50 h of methanol intoxication, attenuated the retinotoxic effects of methanol-derived formate. Our studies document a significant recovery of rod- and cone-mediated function in LED-treated, methanol-intoxicated rats. We further show that LED treatment protected the retina from the histopathologic changes induced by methanol-derived formate. These findings provide a link between the actions of monochromatic red to near-IR light on mitochondrial oxidative metabolism in vitro and retinoprotection in vivo. They also suggest that photobiomodulation may enhance recovery from retinal injury and other ocular diseases in which mitochondrial dysfunction is postulated to play a role.
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PMID:Therapeutic photobiomodulation for methanol-induced retinal toxicity. 1262 62

Previous studies of human primary visual cortex (V1) have demonstrated a significant eye-specific decrease in cytochrome oxidase (CO) staining following monocular enucleation. We have extended these results by examining CO staining and neurofilament labeling in V1 from a patient with long-standing monocular blindness. A pattern of reduced neurofilament reactivity was found to align with pale CO-stained ocular dominance columns. Neurons located within deprived ocular dominance columns were significantly smaller compared with those in nondeprived columns. A spatial analysis of the relationship between CO blobs and ocular dominance columns revealed that both deprived and nondeprived blobs tended to align with the centers of ocular dominance columns.
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PMID:Cytochrome oxidase and neurofilament reactivity in monocularly deprived human primary visual cortex. 1683 56

Blindness leads to a major reorganization of neural pathways associated with touch. Because incoming somatosensory information influences motor output, it is plausible that motor plasticity occurs in the blind. In this work, we evaluated this issue at the peripheral level in enucleated rats. Whisker muscles in enucleated rats 160 days of age or older showed increased cytochrome oxidase activity, capillary density, motor plate size, and amplitude of evoked field potentials as compared with their control counterparts. Such differences were not observed at ages 10 and 60 days, the capillary density was the exception being greater in the enucleated rat at the latter age. Interestingly, there was a trend to increased neurotrophin-3 concentrations in the whisker pads of enucleated rats throughout postnatal development. Our results show that neonatal enucleation leads to late onset plasticity of the whisker's motor system.
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PMID:Late onset muscle plasticity in the whisker pad of enucleated rats. 1883 91

Cytochrome c oxidase (COX) deficiency is one of the most common respiratory chain deficiencies. A woman was presented at the age of 18y with acute loss of consciousness, non-convulsive status epilepticus, slow neurological deterioration, transient cortical blindness, exercise intolerance, muscle weakness, hearing loss, cataract and cognitive decline. Muscle biopsy revealed ragged-red fibers, COX negative fibers and a significant decreased activity of complex IV in a homogenate. Using next generation massive parallel sequencing of the mtDNA, a novel heteroplasmic mutation was identified in MTCO1, m.7402delC, causing frameshift and a premature termination codon. Single fiber PCR showed co-segregation of high mutant load in COX negative fibers. Mutation in mitochondrially encoded complex IV subunits should be considered in mitochondrial encephalomyopathies and COX negative fibers after the common mtDNA mutations have been excluded.
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PMID:Mitochondrial encephalomyopathy with cytochrome c oxidase deficiency caused by a novel mutation in the MTCO1 gene. 2495 8

Xenotransplantation of pig islet cells is a promising alternative for the treatment of diabetes with insulin and may help to prevent numerous late complications such as blindness and amputation. First encouraging results using porcine islets have been reported in preclinical animal models as well in the first clinical trial in New Zealand. The goal of this manuscript is to examine the biological safety of a second trial performed in Argentina, specifically in regards to the transmission of porcine endogenous retroviruses (PERVs) using improved detection methods As in the first trial encapsulated islet cells from the well-characterised Auckland Island pigs were used. The animals were not genetically modified. The islet cells were transplanted in eight human recipients using a modified clinical protocol. Sera taken at different time points after transplantation (up to 55 weeks) were screened for the presence of antibodies against PERV proteins by Western blot analysis using viral antigens from highly purified virus particles. Positive sera obtained by immunization with recombinant PERV proteins were used as control sera. In none of the patients antibodies against PERV were detected, indicating the absence of infection. In parallel at different time points (up to 113 weeks) white blood cells (WBC) have been tested for PERV DNA, and WBC and plasma for PERV RNA by real-time RT-PCR. All tests were negative. In addition, using primers detecting pig mitochondrial cytochrome oxidase (COX) gene, patients were screened for microchimerism. In summary, the data are further evidence for the safety of pig islet cell transplantation.
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PMID:No PERV transmission during a clinical trial of pig islet cell transplantation. 2767 65