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B Pardo

Publications and source records attributed to B Pardo.

34 records · Page 2Linked to original sources
PubMed1993

Ascorbic acid protects against levodopa-induced neurotoxicity on a catecholamine-rich human neuroblastoma cell line.

Levodopa, at concentrations of 0.25 x 10(-4) M or larger, is toxic for the human neuroblastoma cell NB69. Toxicity is associated with high levels of quinones, increased activity of complex II-III, and lack of changes of complex I of the mitochondrial respiratory chain. Deprenyl, which does not alter the production of quinones, has a partial protective effect. Tocopherol, 23 or 115 x 10(-6) M, lacks significant preventive effect on levodopa toxicity, but ascorbic acid, 10(-3) M, prevents levodopa toxicity and quinone formation. Deprenyl, 10(-4) M, provides additional protection in cultures treated with levodopa and ascorbic acid. Our results indicate that ascorbic acid and deprenyl prevent levodopa neurotoxicity by unrelated mechanisms. Both compounds should be considered as complementary drugs to test for slowing the progression of Parkinson's disease.

Ascorbic Acid↗
PubMed1993

Levodopa toxicity in foetal rat midbrain neurones in culture: modulation by ascorbic acid.

Levodopa, a dopamine (DA) precursor administered to patients with Parkinson's disease (PD), produces at 25-200 x 10(-6) M concentrations a dose-dependent reduction of 3H-DA uptake in foetal rat midbrain cultures. Also, a decrease in the number of viable cells and tyrosine hydroxylase (TH) positive neurones, plus disruption of the overall neuritic network are observed concurrently with an elevation of quinone levels in the culture medium. Ascorbic acid (AA), which abolished the quinone overproduction, partially prevented these effects. Though levodopa neurotoxicity in vivo is as yet unproven, AA may reduce vulnerability of endogenous or grafted DA neurones in patients with PD.

Animals↗
PubMed1992

Neurotoxicity of levodopa on catecholamine-rich neurons.

The human neuroblastoma cells NB69 are a catecholamine-rich cell line with pharmacological properties similar to dopamine neurons. This cell line was used to study the neurotoxicity of levodopa on catecholamine neurons. Levodopa, at 50 x 10(-6) M or higher concentrations, produced a dose- and time-dependent reduction in the number of live cells, [3H]thymidine uptake, levels of protein and DNA, and an enhancement of the quinone formation. This is a specific effect of levodopa since it did not happen in NB69 cells incubated with equimolar concentrations of leucine and tryptophan. Treatment with deprenyl, an inhibitor of monoamine oxidase type B, partially prevented levodopa neurotoxicity, suggesting that the mechanism of toxicity was, at least in part, related to an increase in the metabolism of dopamine catalyzed by monoamine oxidase.

Catecholamines↗
PubMed1991

Dietary habits of the middle-aged Warsaw population in 1984 relative to nutritional guidelines.

The dietary habits of 1265 men and 1309 women aged 35-64 years were assessed by food frequencies and 24-h recall. The consumption of fat was high relative to Recommended Dietary Allowances (mean 137% of RDA in the diet of men and 108% in women). The diet was deficient in carbohydrates (80 and 67% respectively), calcium (81 and 64%), vitamin A (84% for both sexes), vitamin B1 (91 and 74%), and vitamin C (41 and 30%). Energy, protein, dietary fibre, iron and vitamin B2 were at the RDA or exceeded it in the men's diet but were insufficient in the women's diet. Fat accounted for 38.5% (men) and 37.7% (women) of energy, with 15.8% of the energy derived from saturated fatty acids and 4.2% from polyunsaturates. The amount of cholesterol consumed was 641 and 452 mg, respectively. This type of diet may contribute to increased incidence of ischaemic heart disease. Only three meals a day were taken by over 83% of the respondents, with over 5-h intervals between meals which may, in addition, contribute to obesity.

Adult↗
PubMed1991

Acute effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in a model of rat designated a poor metabolizer of debrisoquine.

The relationship between oxidative polymorphisms and the cause of Parkinson's disease is controversial. The drug 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which induces parkinsonism in humans and in some animal models, is metabolized by cytochrome P450 db1 isozyme (the same enzymatic system implicated in 4-hydroxylation of debrisoquine). In this study, we treated females of three rat species, which differ in their ability to hydroxylate debrisoquine, with MPTP (three doses of 30 mg/kg s.c. at 12-h intervals), and we measured their motor activity and brain monoamine levels. Female dark-adapted rats (poor metabolizers of debrisoquine) showed a more pronounced and more maintained reduction of their motor activity after treatment with MPTP. MPTP-treated, dark-adapted rats also had a depletion of noradrenaline in the diencephalon and a depletion of dopamine and serotonine and their respective metabolites in the limbic system when compared with the other two species. These results suggest that oxidative polymorphism of debrisoquine plays a role in the acute effects of MPTP.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1980

Nutritional implications of pesticides in foods.

Pesticides having a rapid and positive influence on the quantity of produced food, at the same time are involved in several side effects, often creating some hazard to human health and well-being. The authors show these facts in view of the possible entrance of these substances into the food chain, and present several actions or measures undertaken by various organizations, especially UN Agencies. The main emphasis is laid down on pesticides residues which remain in consumed food, based on the experience gained in different countries including Poland. From the toxicological or health point of view, it is important to know whether these substances interact with other nutrients entering plant or animal tissues or whether they remain on the surface, being easily removed before human consumption. Some effects of processing on decreasing the content of these residues in foodstuffs are also briefly outlined. Another aspect connected with the application of pesticides is their influence (mainly negative) on the nutritive value of harvested plants. In conclusion, the authors call for more attention and a complex approach in using pesticides for plant and animal protection as well as basic and applied nutrition, or health-oriented research along with training activity within national or rather international (e.g. UN Agency) programmes. They should be aimed at the optimal application of pesticides on modern agricultural practices with the main emphasis on their nutritional implication.

DDT↗
PubMedDate not supplied

Articulatory correlates of prosodic control: emotion and emphasis.

This study examines mandibular correlates of prosodic control in nonread dialog exchanges, in which the subject is asked to repeat the same correction of one digit in a three-digit sequence consisting of "five" or "nine" followed by "Pine Street." Articulatory and acoustic data were collected for four speakers of American English at the X-ray Microbeam Facilities at the University of Wisconsin. Jaw opening was measured as vertical jaw position at the time of maximum opening. Middle digits perceived by independent listeners as emphasized generally show jaw opening which is larger than the average jaw opening for the utterances in which they occur. As the speaker repeatedly makes the same correction, not only does jaw opening increase significantly on the corrected digit but also the overall amount of jaw opening on all digits in the corrected exchanges increases. Independent separate perception tests show that listeners also perceive the speakers' answers to be more irritated as the speaker repeats the same correction. The findings suggest a local and global use of the jaw opening gesture to produce both linguistic or paralinguistic and extralinguistic information, that is, word emphasis and the emotional tenor of the dialog itself.

Adult↗
PubMedDate not supplied

[Daily fat consumption by the population of Warsaw].

Fat intake with the diet has been assessed within screening Pol-MONICA--Warsaw Project in randomly selected sample of Warsaw inhabitants aged between 35 and 64 years. Altogether 2571 individuals have been screened. Fat intake in daily diet has been estimated by the 24-hour recall technique. In men, fat intake covered 38.4% of the total energy supply with the diet whereas in female population - 37.7%. Mean contribution of SFA and P/S ratio in both sex groups have been 15.8% and 0.285, respectively. Daily cholesterol intake has been 641 mg (224 mg/1000 kcal) in male and 456 mg (227/1000 kcal) in female population. These values did not change significantly with the age of the screened individuals. Such a diet may be considered atherogenic.

Adult↗
PubMedDate not supplied

[Effect of the calcium channel blockers on rotation induced by apomorphine and amphetamine in rats lesioned with 6-hydroxydopamine].

We have studied the effects of calcium channel blockers cinarizine, flunarizine, nicardipine, nifedipine, verapamil and diltiazem on the motor anomalies which can be found in rats with unilateral nigrostriated lesion due to 6-OH-DA. All of them reduce rotation induced by apomorphine according to this order: nifedipine greater than nicardipine greater than diltiazem greater than flunarizine greater than verapamil greater than cinarizine. No effects on rotation induced by amphetamine have been observed. Our data suggest that calcium channel blockers cause dopamine receptor blockade but they do not modify the calcium-non-depending releasing of dopamine induced by amphetamine.

Amphetamine↗
PubMedDate not supplied

[The effect of calcium channel blockers on myoclonus induced by DDT].

Behaviour syndrome induced by P, p'-DDT in rats constitutes an experimental pattern of myoclonia whose neurochemical basis is not yet clear. In this paper, effects of some calcium canal antagonists (CCA) have been studied. Nicardipine, verapamil and diltiazem significantly reduce myoclonia intensity, whereas flunarizine and cinarizine (the two diphenylalkylamines) enhance it. Mechanisms involved are unknown and it is not possible to foresee the clinical usefulness of CCA in these changes.

Animals↗
PubMedDate not supplied

Intracerebroventricular infusion of dopamine and its agonists in rodents and primates. An experimental approach to the treatment of Parkinson's disease.

The authors investigated the effects of chronic intracerebroventricular (ICV) infusion of dopamine (DA) and DA agonists in animal models of DA deficiency in rodents and primates. Rats with unilateral nigrostriatal lesions induced by 6-OH-DA received infusions of DA, pergolide, lisuride, and (+)-4-propyl-9-hydroxynaphthoxacine (PHNO) for from 1 to 2 weeks through a catheter implanted into the cerebral ventricle ipsilateral to the lesion and connected to an osmotic minipump filled with the active substance. The infused animals had persistent contralateral rotation during the period of infusion. The DA infusion restored DA levels in lesioned animals. In animals treated chronically with reserpine, the ICV DA infusion restored DA levels in the brain, but akinesia was not reversed unless monoamine oxidase inhibiters were also given, intraperitoneally or ICV, with the DA infusion. An ICV infusion of PHNO reversed reserpine-induced akinesia. The infusion of DA or PHNO restored normal patterns of behavior in monkeys made akinetic by treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), but the infusion was complicated by intolerance to the pump or frequent disconnection of the catheter. An ICV infusion of PHNO may be an alternative experimental approach to the treatment of fluctuations in patients with Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗