Biomedical subjects

Robert Rejdak

Publications and source records attributed to Robert Rejdak.

22 records · Page 2Linked to original sources

PubMed2002

Pharmacodynamics of citicoline relevant to the treatment of glaucoma.

Citicoline (exogenous CDP-choline) is a nontoxic and well-tolerated drug used in pharmacotherapy of brain insufficiency and some other neurological disorders, such as stroke, brain trauma, and Parkinson's disease. A few reports indicate that citicoline treatment may also be beneficial in glaucoma. Currently glaucoma is considered a neurodegenerative disease in which retinal ganglion cells (RGC) slowly die, likely in the apoptotic mechanism. Endogenous CDP-choline is a natural precursor of cellular synthesis of phospholipids, mainly phosphatydylcholine (PtdCho). Enhancement of PtdCho synthesis may counteract neuronal apoptosis and provide neuroprotection. Citicoline, when administered, undergoes a quick transformation to cytidine and choline, which are believed to enter brain cells separately and provide neuroprotection by enhancing PtdCho synthesis; similar effect may be expected to occur in glaucomatous RGC. Furthermore, citicoline stimulates some brain neurotransmitter systems, including the dopaminergic system, and dopamine is known as a major neurotransmitter in retina and postretinal visual pathways. In a double-blind, placebo-controlled study, treatment of glaucoma resulted in functional improvement in the visual system noted with electrophysiological methods. Development of citicoline as a treatment for glaucoma is indicated.

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PubMedDate not supplied

Citicoline treatment increases retinal dopamine content in rabbits.

Citicoline (exogenous cytidine-5'-diphosphocholine) was reported to enhance dopaminergic neurotransmission in the brain. A few clinical studies showed beneficial effects of this drug on the function of the visual pathway in patients with glaucoma or amblyopia. The present study was aimed at determining whether citicoline could influence retinal catecholamine levels in adult male Albino rabbits. The animals received the drug (50 mg/kg i.p., twice daily) or vehicle for 7 days, and retinal catecholamine concentrations were determined by HPLC. Compared to vehicle-treated controls, citicoline-treated animals displayed a significantly higher retinal dopamine concentration and a tendency toward an increase in adrenaline concentration, while the noradrenaline concentration remained unchanged. It is, therefore, conceivable that citicoline reinforces dopaminergic transmission in the retina.

Animals↗

PubMedDate not supplied

Content of kynurenic acid and activity of kynurenine aminotransferases in mammalian eyes.

The present study investigated the kynurenic acid (KYNA) contents and kynurenine aminotransferase (KAT I and II) activity in structures of the human, monkey, rabbit and bovine eye. KYNA levels were investigated with HPLC and detected fluorimetrically. The activity of KAT I and II was assayed as quantitative analysis of newly synthesized KYNA in vitro. Mean KYNA levels (+/-SD) in the human retina and vitreous body were 36.8 +/- 7.6 and 33.1 +/- 6.2 pmol/g wet tissue weight, respectively. In human eyes, KAT I activity in the vitreous body was 0.57 +/- 0.28, that of KAT II was 2.56 +/- 0.69. KAT I activity in the retina was 3.42 +/- 1.17 and that of KAT II 10.75 +/- 9.2. (KAT activity is expressed as KYNA synthesis in picomoles per gram wet tissue weight per hour.) The values of KYNA and KAT observed in other mammalian species tested were in the same range. In conclusion, KYNA and KAT enzymatic activity are present in the structures of human and other mammalian eyes.

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PubMedDate not supplied

Retinopathy of prematurity: A refresher for obstetricians.

Advances in neonatal care improved the survival of many preterm infants, but also increased the incidence of retinopathy of prematurity (ROP). Numerous risk factors have been associated with the development of ROP, the most important of which are: low birth weight, early gestational age at delivery, and duration of oxygen therapy. Screening premature infants is a critical factor for any prevention and treatment protocol. The Retinopathy of Prematurity Subcommittee of the American Academy of Ophthalmology (AAO) and the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) have developed guidelines that assist practicing physicians in managing children with ROP. A portion of these guidelines is particularly applicable to practicing obstetricians who, along with the pediatricians, are often the primary physicians for the affected families. The aim of this paper is to present a comprehensive overview of the epidemiology, etiology, manifestations, prevention, and management of ROP. In the last section, the authors present guidelines for practicing obstetricians that incorporate the most recent recommendations of ophthalmic and pediatric thought leaders.

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