Vaimse arengu mahajäämuse geneetilised põhjused: X-liiteline vaimse arengu mahajäämus

Üheks kõige sagedasemaks raske puude põhjuseks lastel ja noortel on vaimse arengu mahajäämus (VAM). Vaatamata sellele, et välja on töötatud palju erinevaid uurimis meetodeid, jääb enamik neist patsientidest praegugi veel täpse diagnoosita. Viimastel aastatel on uuringute tähelepanu keskpunkti tõusnud X-kromosoom, kuna on leitud, et võrreldes autosoomidega esineb X-kromosoomis märgatavalt rohkem geene, mis muteerununa põhjustavad VAMi. Artiklis on kirjeldatud teadaolevalt sagedasemaid X-liitelise vaimse arengu mahajäämuse sündroome ning toodud välja autismi seni leitud seosed X-liitelise VAMiga. Eesti Arst 2007; 86 (4): 239–24

Detection of tmRNA molecules on microarrays at low temperatures using helper oligonucleotides

<p>Abstract</p> <p>Background</p> <p>The hybridization of synthetic <it>Streptococcus pneumoniae </it>tmRNA on a detection microarray is slow at 34°C resulting in low signal intensities.</p> <p>Results</p> <p>We demonstrate that adding specific DNA helper oligonucleotides (chaperones) to the hybridization buffer increases the signal strength at a given temperature and thus makes the specific detection of <it>Streptococcus pneumoniae </it>tmRNA more sensitive. No loss of specificity was observed at low temperatures compared to hybridization at 46°C. The effect of the chaperones can be explained by disruption of the strong secondary and tertiary structure of the target RNA by the selective hybridization of helper molecules. The amplification of the hybridization signal strength by chaperones is not necessarily local; we observed increased signal intensities in both local and distant regions of the target molecule.</p> <p>Conclusions</p> <p>The sensitivity of the detection of tmRNA at low temperature can be increased by chaperone oligonucleotides. Due to the complexity of RNA secondary and tertiary structures the effect of any individual chaperone is currently not predictable.</p

Haploinsufficiency of EHMT1 improves pattern separation and increases hippocampal cell proliferation

Contains fulltext : 169681.pdf (publisher's version ) (Open Access)Heterozygous mutations or deletions of the human Euchromatin Histone Methyltransferase 1 (EHMT1) gene are the main causes of Kleefstra syndrome, a neurodevelopmental disorder that is characterized by impaired memory, autistic features and mostly severe intellectual disability. Previously, Ehmt1+/- heterozygous knockout mice were found to exhibit cranial abnormalities and decreased sociability, phenotypes similar to those observed in Kleefstra syndrome patients. In addition, Ehmt1+/- knockout mice were impaired at fear extinction and novel- and spatial object recognition. In this study, Ehmt1+/- and wild-type mice were tested on several cognitive tests in a touchscreen-equipped operant chamber to further investigate the nature of learning and memory changes. Performance of Ehmt1+/- mice in the Visual Discrimination &Reversal learning, object-location Paired-Associates learning- and Extinction learning tasks was found to be unimpaired. Remarkably, Ehmt1+/- mice showed enhanced performance on the Location Discrimination test of pattern separation. In line with improved Location Discrimination ability, an increase in BrdU-labelled cells in the subgranular zone of the dentate gyrus was observed. In conclusion, reduced levels of EHMT1 protein in Ehmt1+/- mice does not result in general learning deficits in a touchscreen-based battery, but leads to increased adult cell proliferation in the hippocampus and enhanced pattern separation ability

Ligandi sidumine 5-HT1A retseptorile ja selle modulatsioon Mg2+ ja Mn2+ poolt

Väitekirja elektroonilisest versioonist puuduvad varem avaldatud publikatsioonide täistekstidIn the first part of this thesis the binding of 5-HT1A receptor specific antagonist [3H]WAY100635 to rat brain membranes was characterized. It was found, that the binding on lower concentrations was considerably slow, and a notable amount of receptors will be inactivated before thermodynamic equilibrium can be reached, yet on higher concentrations rapid increase in reaction rate indicative of cooperative binding was detected. This means that [3H]WAY100635 is an excellent tool for determining receptor number in a given sample, but not a very good ligand in equilibrium binding studies. In the second part of this thesis the influence of Mn2+ in comparison to Mg2+ to signal transduction via 5-HT1A receptors was measured. It was shown that Mn2+ can stabilize greater number of agonist high-affinity binding sites, while the size of this effect depended on the used brain region (different in hippocampal and cortical membranes) and also on the GTPγS concentration. Since GTPγS activates G-proteins, sensitivity to its concentration refers to the involvement of G-proteins in the enhancing regulation by Mn2+. Sf9 cell lines were created for comparison expressing only 5-HT1A receptor or the receptor with Gi or Gs protein. Agonist high affinity binding was achieved only in cell line expressing the receptor with Gi protein, and the sensitivity of this cell line to Mn2+ was similar to cortical preparations but different from hippocampal membranes. To clarify the role of G-proteins on this regulation, influence of Mn2+ compared to Mg2+ to the affinity of guanosine nucleotides (GDP and GTPγS) binding to G-proteins was measured. Mn2+ lowered the affinity of both GDP and GTPγS compared to Mg2+, and the size of the effect was again dependent on used brain region, showing that there are differences in the composition of signaling complexes that are formed with 5-HT1A receptor in different brain regions. Additionally there seem to be differences in the sensitivity of these complexes to Mn2+-ions.Antud töö esimeses osas iseloomustati 5-HT1A retseptori spetsiifilise antagonisti [3H]WAY100635 sidumist roti aju rakumembraanidele ning leiti, et ligandi sidumise kiirus on madalamatel kontsentratsioonidel liiga aeglane, et saavutada termodünaamiline tasakaal enne märkimisväärse hulga retseptorite inaktiveerumist, kõrgematel kontsentratsioonidel toimus aga reaktsiooni järsk kiirenemine, mis viitab sidumise kooperatiivsusele. Seega on [3H]WAY100635 hea ligand 5-HT1A retseptorite kontsentratsiooni määramiseks, kuid selle rakendamine ligandide afiinsuse määramiseks tasakaalulises katses on vägagi piiratud. Töö teises osas uuriti Mg2+ ja Mn2+-ioonide mõju 5-HT1A retseptoriga seotud signaaliülekandele. Leiti et Mn2+ suudab stabiliseerida suurema hulga agonisti kõrge afiinsusega sidumissaite ning efekti suurus on erinevates aju osade rakumembraanides erinev (erinevus hipokampuse ja korteksi membraanide vahel) ning sõltuvuses GTPγSi kontsentratsioonist. Et GTPγS aktiveerib G-valke, viitab kontsentratsioonitundlikkus retseptoriga seotud G-valkude osalusele Mn2+ poolsel agonist kõrge afiinsusega sidumiskohtade suurendamisel. Selle hüpoteesi kinnitamiseks kasutati Sf9 rakuliine, kuhu oli ekspresseeritud kas ainult 5-HT1A retseptor, või 5-HT1A retseptor koos Gi või Gs valguga. Agonisti kõrge affinsusega sidumine saadi vaid preparaadis, kus koos retseptoriga ekspresseerus Gi valk, ning selle preparaadi tundlikkus Mn2+-le sarnanes korteksi membraanidele, kuid erines hipokampuse membraanide tundlikkusest. Et selgitada täpsemalt kuidas G-valgud osalevad Mn2+ poolses regulatsioonis, mõõdeti kuidas muutub guanosiinnukleotiidide (GDP ja GTPγS) afiinsus Mg2+ asendamisel Mn2+-ga, ja leiti et Mn2+ juuresolekul on guanosiinnukleotiidide afiinsus G-valgule oluliselt väiksem, samuti esines efekti suuruse erinevus aju osade vahel. See tulemus näitab, et ilmselt on 5-HT1A retseptoriga moodustuvad signaaliülekande kompleksid erinevates aju osades erinevad, nagu ka nende komplekside tundlikkus Mn2+-ioonile

Applications of fungal enzymes to clean the environment

Eden večjih okoljskih problemov danes je onesnaženje s strupenimi kemikalijami, ki predstavljajo resno tveganje za okolje in ljudi. To je vidno tudi iz zadnjih okoljskih nesreč v Sloveniji. Določene vrste gliv, predvsem glive bele trohnobe, so zaradi nespecifičnosti zunajceličnih encimov (lakaze, lignin peroksidaze, od mangana odvisne peroksidaze) privlačne za uporabo pri razgradnji onesnažil, prisotnih v okolju. Čiščenje oz. vračanje okolja v prvotno stanje z uporabo gliv oz. njihovih encimov imenujemo mikoremediacija. Glive so sposobne razgradnje onesnažil, kot so policiklični aromatski ogljikovodiki, polietilen, nafta in naftni proizvodi, različni insekticidi, poliklorirani bifenili in drugi. Razgradnjo omogoča podobnost med strukturo lignina in strukturo teh onesnažil. Glivne encime lahko uporabimo v bioreaktorju ali pa v procesu bioaugmentacije ali biostimulacije.One of the main environmental problems today is the pollution of the environment caused by toxic chemicals, which pose a serious risk for the ecosystem and the people involved. This is evident from the latest environmental accidents in Slovenia. Certain species of fungi, mainly white rot fungi, are able to degrade many pollutants present in the environment, due to the non-specifity of their extracellular enzymes (laccases, lignin peroxidases, manganese peroxidases), thus making them an attractive alternative for cleaning the environment. Cleaning or returning the environment to its original state with the use of fungi or its enzymes is called mycoremediation. Similarity between the chemical structure of lignin and the structures of many pollutants enables fungi to degrade a wide range of pollutants such as polycyclic aromatic hydrocarbons, polyethylene, oil, insecticides, polychlorinated biphenyls and others. Fungal enzymes can be used in a bioreactor, in addition to approaches of bioaugumentation or biostimulation

Characterization of visible and subvisible protein particles in biopharmaceuticals

Monoklonska protitelesa so beljakovinske molekule, ki so nagnjene k agregaciji, kar za biološko zdravilo ni sprejemljivo, saj lahko poveča imunogenost končnega produkta. Dolgoročno stabilnost proteina ocenimo z merjenjem proteinske agregacije v vzorcih, ki so izpostavljeni povišanim temperaturam in kasnejšo ekstrapolacijo podatkov z uporabo različnih modelov. Glede na različne mehanizme nastajanja agregatov, kinetiko agregacije ter adhezije delcev na površino vial lahko pri dejanskih dolgoročnih pogojih shranjevanja pride do višje koncentracije delcev v raztopini, ki je ni mogoče napovedati na tak način. V nalogi smo preučevali vpliv površine viale, temperature shranjevanja in prisotnosti soli na kinetiko procesa agregacije na več velikostnih skalah agregatov za dve različni monoklonski protitelesi. Pri obeh smo določili, da so pri koncentracijah, značilnih za biološka zdravila, omejujoč korak hitrosti agregacije bimolekularni trki. Hitrost agregacije lahko pri poljubni temperaturi in koncentraciji napovemo le za enega od testiranih monoklonskih protiteles, medtem ko pri drugem dodaten neznan proces povzroča odstopanje dejanskih rezultatov od napovedi. To predstavlja povečano tveganje pri izbiri formulacije na podlagi presejalnih testov pri povišani temperaturi in nizki koncentraciji, ki pa ga lahko zmanjšamo z dodatnimi temperaturnimi in koncentracijskimi pogoji testiranja.Monoclonal antibodies are protein molecules that are prone to aggregation, which is not acceptable for biopharmaceuticals, since it can increase the immunogenicity of the final product. Long-term protein stability can be assessed by measuring protein aggregation in samples exposed to elevated temperatures and subsequent extrapolation of data using different models. Due to different mechanisms of aggregate formation, aggregation kinetics and particle adhesion to the vial surface, higher particle concentrations in solution may occur under actual long-term storage conditions, which cannot be predicted from accelerated studies. We studied the effect of vial surface, temperature and presence of salt on the kinetics of aggregation process on multiple size ranges of aggregates for two monoclonal antibodies. Bimolecular collisions were found to be the limiting step of aggregation at concentrations specific to biologics. The rate of aggregation can be predicted at any temperature or concentration for only one of the tested monoclonal antibodies, while the other is likely to undergo an additional unknown process, which causes a deviation of prediction from the actual results. This poses an increased risk when selecting a formulation based on screening tests at elevated temperatures and low concentrations, which can be mitigated by additional temperature and concentration conditions

Development and validation of a film and instructional manual for teaching throwing to Pre and Elementary school children

Includes bibliographical references (pages 36-38)An inservice training film and manual on the development of the overhand throw was prepared for the use of pre-school and elementary school teachers for teaching the skill of throwing. To validate the usefulness of this film and manual, a study was conducted. The study lasted for twelve school days and involved 140 students in preschool, kindergarten,and first grade. The experimental kindergarten and first grades were at the Rio plaza Elementary School and the control kindergarten and first grades were at the Rio Real Elementary School both in the Rio School District. There were only two preschool classes in the district, both at the El Rio Elementary School, hence one class served as the experimental group and the other the control group. (See more in text.