Investigating Bacterial Contributions and Novel Inhibitors to Enhance Levodopa Efficacy in Parkinson’s Disease

Parkinson's disease (PD) is a brain disorder that gradually reduces dopamine levels, causing symptoms like tremors and stiffness. The most common treatment involves levodopa, a precursor that the body converts into dopamine. However, an enzyme called dopa decarboxylase (DDC) can convert levodopa into dopamine before it reaches the brain. To prevent this, levodopa is given with a DDC inhibitor. Yet, not all patients respond equally. One reason for this variation is the presence of certain gut bacteria that carry an enzyme called tyrosine decarboxylase (TDC), which also converts levodopa into dopamine, unaffected by the DDC inhibitor.In my PhD thesis, we investigated this problem. Using advanced computer simulations, we compared the structure of the human enzyme DDC with the bacterial enzyme TDC. Then, in experiments with rats, we tried increasing the levels of the existing DDC inhibitors to see if they could also block TDC. Unfortunately, this approach didn’t work. Next, we tested a variety of chemical compounds to see if any could inhibit TDC effectively. We identified a few promising candidates. However, we still need to test whether these compounds might also affect the human enzyme DDC and whether they are safe for use in people.This research is a step forward in the ongoing quest to improve treatments for Parkinson's disease. While there’s still work to be done, the insights gained from these studies bring us closer to a solution that could make a real difference in the lives of those affected by this challenging condition

MECHANISMS OF PLATELET ACTIVATING FACTOR (PAF) ACTIONS ON MOUSE

THE MECHANISMS OF ACTIONS OF PAF ON MOUSE WERE INVESTIGATED IN ORDER (A) TO DESCRIBE PAF INTERACTIONS WITH THE BLOOD AND (B) TO EXPLAIN THE INCREASED RESISTANCE OF MOUSE. PART OF THIS RESISTANCE RESULTS FROM THE FAST HYDROLYSIS AND THE BINDING OF PAF TO THE BLOOD CELLS. THE BINDING WITH HIGH AFFINITY OF PAF TO MOUSE AND HUMAN PLATELETS INDICATES THE PRESENCE OF SPECIFIC RECEPTORS ALTHOUGH WE COULD NOT REACH SATURATION. INTRAVENOUS INJECTION OF PAF ON MICE RESULTS IN SEVERE HEMOCONCENTRATION AND LEUCOPENIA. THE INHIBITION OF LETHAL PAF ACTIONS FROMTHE COMBINATION OF PROMETNAZINE AND CHLORPROMAZINE INDICATES THE MEDIATION OF THESE ACTIONS BY THE COMBINATION OF HISTAMINE AND SEROTONINE.ΜΕΛΕΤΗΘΗΚΑΝ ΒΙΟΧΗΜΙΚΑ ΚΑΙ ΦΑΡΜΑΚΟΛΟΓΙΚΑ ΟΙ ΜΗΧΑΝΙΣΜΟΙ ΔΡΑΣΗΣ ΤΟΥ PAF ΣΤΟΝ ΠΟΝΤΙΚΟ ΜΕ ΣΤΟΧΟ (Α) ΤΗ ΠΕΡΙΓΡΑΦΗ ΤΗΣ ΣΥΜΠΕΡΙΦΟΡΑΣ ΤΟΥ ΣΤΟ ΑΙΜΑ ΚΑΙ (Β) ΤΗΝ ΕΞΗΓΗΣΗ ΤΗΣ ΑΥΞΗΜΕΝΗΣ ΑΝΤΟΧΗΣ ΤΟΥ ΟΔΟΝΤΙΚΟΥ. ΜΕΡΟΣ ΤΗΣ ΑΝΤΟΧΗΣ ΤΟΥ ΠΟΝΤΙΚΟΥ ΜΠΟΡΕΙ ΝΑ ΑΠΟΔΩΘΕΙ ΣΤΗ ΜΕΓΑΛΗ ΤΑΧΥΤΗΤΑ ΥΔΡΟΛΥΣΗΣ ΚΑΙ ΣΤΗΝ ΙΣΧΥΡΟΤΕΡΗ ΔΕΣΜΕΥΣΗ ΤΟΥ PAF ΣΤΑ ΚΥΤΤΑΡΑ ΤΟΥ ΑΙΜΑΤΟΣ. Η ΧΑΡΑΚΤΗΡΙΖΟΜΕΝΗ ΑΠΟ ΜΕΓΑΛΗ ΣΥΓΓΕΝΕΙΑ ΔΕΣΜΕΥΣΗ ΤΟΥ PAF ΑΠΟ ΤΑ ΑΙΜΟΠΕΤΑΛΙΑ ΤΟΥ ΑΝΘΡΩΠΟΥ ΚΑΙ ΤΟΥ ΑΡΟΥΡΑΙΟΥ ΥΠΟΔΕΙΚΝΥΕΙ ΤΗ ΠΑΡΟΥΣΙΑ ΕΙΔΙΚΩΝΥΠΟΔΟΧΕΩΝ ΠΟΥ ΟΜΩΣ ΔΕΝ ΠΑΡΟΥΣΙΑΖΟΥΝ ΚΟΡΕΣΜΟ. Η ΧΟΡΗΓΗΣΗ ΤΟΥ PAF IN VIVO ΠΡΟΚΑΛΕΙ ΑΙΜΟΣΥΓΚΕΝΤΡΩΣΗ ΚΑΙ ΛΕΥΚΟΠΕΝΙΑ. Η ΑΝΑΣΤΟΛΗ ΤΗΣ ΘΑΝΑΤΗΦΟΡΑΣ ΔΡΑΣΗΣ ΤΟΥ PAF ΑΠΟ ΤΟ ΣΥΝΔΥΑΣΜΟ ΥΔΡΟΜΕΘΑΛΙΝΗΣ ΧΛΩΡΟΠΡΟΜΑΖΙΝΗΣ ΥΠΟΔΕΙΚΝΥΕΙ ΤΗ ΜΕΣΟΛΑΒΗΣΗ ΤΟΥ ΣΥΝΔΥΑΣΜΟΥ ΙΣΤΑΜΙΝΗ ΣΕΡΟΤΟΝΙΝΗ ΣΤΗΝ ΕΚΔΗΛΩΣΗ ΤΗΣ

High-Throughput Methods for Detection of Genetic Variation

Understanding human genetic variation is currently believed to reveal the cause of individual susceptibility to disease and the large variation observed in response to treatment. In this review, we will focus on different approaches to identify and visualize genetic alterations. The various approaches for allele discrimination are formally systematically divided into (i) enzymatic approaches, in which the properties of different enzymes to discriminate between nucleotides are used (restriction enzymes type II, Cleavase and Resolvase, DNA polymerase, and ligase); (ii) electrophoretic methods, in which the allele discrimination is based on the difference in mobility in polymeric gels or capillaries (single- and double-stranded conformation assays, heteroduplex analysis, and DNA sequencing); (iii) solid-phase determination of allelic variants, including high-density oligonucleotide arrays for hybridization analysis, minisequencing primer extension analysis, and fiberoptic DNA sensor array; (iv) chromatographic methods such as denaturing high-performance liquid chromatography (DHPLC); (v) other physical methods of discrimination of allelic variants such as mass spectrometry (mass and charge) or fluorescence exchange-based techniques; and (vi) in silico methods such as high-throughput analysis of expressed sequence tag data. The most frequently used techniques and instrumental settings applied in different combinations are described, and other methods that are less broadly used but have interesting potentials are discussed

Study of Digoxin as inhibitor of the in vivo effects of acetyl glyceryl ether phosphorycholine (AGEPC) in mice

Acetyl glyceryl ether phosphorylcholine (AGEPC) and the cardiac glycoside digoxin were administered intravenously through the tail vein into ether-anesthetized SWR mice (two months old). The administered doses were 0.18 nmol AGEPC/ g.b.w. (a lethal one) and 75 or 125 ng digoxin/b.w. Digoxin ameliorates the effects of the lethal dose of AGEPC showing maximum activity when given 5 or 10 min after AGEPC administration to female and male animals respectively. Digoxin shows also a protective action towards the effects of AGEPC and maximum activity appears when it is given 10 min before AGEPC administration. In agreement with the picture of increased survival in digoxin pretreated animals, are our findings on life prolongation of mice which finally die from AGEPC, the amelioration of the expected fall in blood platelet counts after AGEPC administration as well as the improved performance of the animals in a series of physical tests. © 1988