Spelling suggestions: "subject:"genotipado"" "subject:"genotipagem""
1 |
Efecte del genotip halotà i la línia paterna en el comportament, productivitat, qualitat de canal i carn i benestar animal en porcíFàbrega i Romans, Emma 18 June 2002 (has links)
El gen de l'halotà ha estat vinculat a un augment de la qualitat de canal porcina, que s'acompanya, però, d'una disminució de la qualitat de carn i del benestar animal. Per aquest motiu, aquest treball pretenia respondre si existirien alternatives econòmicament viables a l'ús del gen halotà, que permetessin disminuir les seves repercussions negatives a nivell de qualitat de carn i benestar sense afectar els seus avantatges en qualitat de canal.Per tal d'aconseguir aquests objectius, es va fer el seguiment de dos lots d'animals, des de la maternitat fins al sacrifici. Aquests dos lots d'individus es van diferenciar fonamentalment en la línia paterna utilitzada: dues línies heterozigotes pel gen halotà en el primer lot, una de raça Pietrain i l'altra híbrida Large White¥Pietrain, i tres línies Pietrain en el segon lot, dues lliures del gen i una homozigota recessiva. Alhora, es van recollir mostres en dos escorxadors per tal de determinar les freqüències de mortalitat per cada genotip. Els resultats es van agrupar en cinc capítols en funció de la naturalesa dels experiments d'on es van obtenir i dels factors avaluats. En el primer capítol es van agrupar tots els resultats de conducta individual i social, tant de garrins com de porcs d'engreix. El segon i tercer capítol corresponen als resultats de qualitat de carn i canal i fisiologia d'estrès determinats després de sotmetre als animals a tractaments previs al sacrifici diferents. El quart capítol recull les dades obtingudes en el Centre de Control Porcí (centre de l'Institut de Recerca i Tecnologia Agroalimentàries) sobre productivitat i conducta alimentària. Finalment, el darrer capítol tracta sobre les freqüències de mortalitat estimades per a cada genotip. Aquests capítols estan precedits d'una introducció general i seguits per una breu discussió general dels resultats i conclusions. Les conclusions del treball foren que, en relació a la conducta social i alimentària, el genotip halotà va mostrar un efecte poc consistent al llarg del temps, inferior al d'altres factors estudiats com l'edat dels individus o l'horari d'observació. Contràriament, es van obtenir indicis per suggerir que el genotip podria influir la resposta individual dels porcs a situacions de novetat o en condicions estressants com les plantejades durant un transport a l'escorxador, de manera que els individus heterozigots foren més reactius. Pel què fa a la qualitat, el genotip heterozigot va estar associat a un major contingut de magre de les canals i de pernil, però alhora a una pitjor qualitat de carn i benestar. La mortalitat durant el transport i espera fou clarament superior pels porcs nn i Nn, comparat amb els NN. Contràriament, els efectes de la línia paterna foren significatius sobre la qualitat de canal, conducta alimentària i productivitat, però poc importants pel què fa la qualitat de carn i benestar. La conclusió general fou, per tant, que algunes línies paternes millorades com les de l'estudi podrien representar una bona alternativa al genotip halotà, en la mesura que no disminueixen la qualitat de canal i els seus efectes sobre la qualitat de carn i benestar són molt inferiors. / Halothane gene has been associated with an increase in porcine carcass quality, alongside a negative effect on meat quality and animal welfare. For this reason, the main objective of this work was to determine whether there would be feasible alternatives on economical grounds to the use of the gene that could bring similar positive effects on carcass quality without compromising meat quality and animal welfare. In order to answer this question, two batches of pigs were observed from the farrowing pens to the abattoir. The main difference between these two batches was the terminal sire line used: two heterozygous sire lines in batch 1, a Pietrain and a Large White¥Pietrain, and three Pietrain lines in batch 2, two of them free of the halothane gene and a homozygous recessive. Moreover, samples of pigs which died during transport or at lairage were collected at two abattoirs to determine within genotype frequencies of mortality. The results have been organized in five chapters according to the type of experiments or effects evaluated. The first chapter summarize the results on individual and social behaviour of both piglets and growing pigs. The second and third chapter show the results related to meat and carcass quality and stress physiology obtained after delivering the pigs to the abbatoir under different pre-slaughter treatments. The forth chapter deals with the results obtained at the Pig Testing Centre about performance and feeding behaviour. Finally, the last chapter reflects the mortality rates estimated for each genotype. This chapters are preceded by a general introduction and followed by a brief general discussion of the results and conclusions. The conclusions of this work were that, in relation to social and feeding behaviour, halothane genotype did not show a consistent effect, and it was surpassed by the effect of other factors such as age of pigs or time of day of observation. In contrast, the results suggested that Nn pigs could be more reactive when challenged in a novel situation or when subjected to stressful conditions like transportation to the abattoir. In relation to quality, heterozygous pigs did present carcass with a higher lean content and primal cut yield, but it was associated also with a lower meat quality and poorer animal welfare compared to halothane free pigs. Mortality rates were clearly higher for nn and Nn pigs compared to NN. Conversely, terminal sire line significantly affected those parameters of carcass quality, feeding behaviour and performance, but its effects on meat quality and welfare were less important compared to those of halothane genotype. Therefore, the general conclusion was that improved terminal sire lines, like halothane free Pietrain lines, could bring similar effects than halothane genotype in terms of carcass quality, without compromising meat quality and welfare.
|
2 |
Estudi citogenètic-molecular de la Síndrome de DownNadal Sánchez, Margarida 22 December 2000 (has links)
Els pacients amb síndrome de Down (SD) deguda a trisomia parcial del cromosoma 21 (HSA21), han estat històricament estudiats per tal d'establir correlacions entre el genotip i el fenotip. La caracterització citogenètica, molecular i clínica d'aquests pacients és essencial. Donada la gran heterogeneitat fenotípica i la manca de penetració de la majoria dels trets clínics, per tal d'establir comparacions fiables, és important definir els punts de trencament en cada cas així com fer-ne una caracterització clínica exhaustiva. S'han identificat sis pacients amb SD deguda a trisomia parcial del HSA21, quatre dels quals impliquen només aquest cromosoma. Dos dels pacients presenten una translocació que comporta una monosomia parcial dels cromosomes 13 i 15 respectivament; dos pacients presenten una duplicació directa que comprèn des del marcador D21S302 fins el telòmer; un altre pacient presenta una translocació entre 21q i 21p; finalment, s'ha identificat un pacient amb una duplicació intersticial del YAC 876d4 el qual conté el gen GART. Els punts de trencament han estat caracteritzats mitjançant FISH fent servir com a sondes, un contigu de YACs de 21q, el quimerisme dels quals va ser prèviament estudiat. L'avaluació clínica va ser feta en cada cas per l'equip clínic que referia el pacient, tots d'acord el mateix protocol. Els sis pacients defineixen quatre trisomies segmentàries diferents: des de D21S302 fins el telòmer, des de D21S226 fins el telòmer, des de CBR també fins el telòmer i finalment, un cas només comprèn la regió entre els marcadors D21S216 i D21S323. Per als trets clínics que no són totalment penetrants, les comparacions clíniques es basen només en la seva presència. Els resultats indiquen que la majoria d'alteracions clíniques de la SD mapen al terç distal de 21q, tal com ja s'havia postulat a la literatura. Si es comparen els resultats amb d'altres previàment publicats, es pot concloure que: 1/. l'estenosi duodenal queda restringida a la regió compresa entre els marcadors D21S59 i D21S302, 2/. la llengua escrotal mapa entre el centròmer i D21S302, 3/. la hipotonia es pot excloure de la regió compresa entre D21S216 i D21S323, 4/. finalment, donat que el gen APP queda exclòs de totes les trisomies estudiades i dos dels pacients estudiats són majors de 30 anys i no presenten cap signe de la malatia d'Alzheimer, es pot sustentar la hipòtesi que la trisomia d'APP és necessària per a desenvolupar aquesta malaltia en la SD. La caracterització d'aquests casos de SD, ha permès poder oferir assessorament genètic a les famílies dels pacients, especialment en aquells casos en què el reordenament cromosòmic és d'origen familiar. En aquest treball també s'ha aplicat la FISH per al mapatge en cromosomes humans d'alguns dels gens del HSA21 identificats al Grup de Recerca de la SD del Centre de Genètica Mèdica i Molecular de l'IRO. Finalment, la FISH també s'ha fet servir per a determinar el nombre i la localització de la inserció de transgens en dos models murins de la SD generats al mateix laboratori. / Down syndrome (DS) patients with partial trisomy of chromosome 21 (HSA21) have historically been studied to establish correlations between the phenotype and the genotype. Thus, cytogenetic, molecular and clinical characterisation of these patients is essential. Given the high heterogeneity and the lack of penetrance of most of the features, to make reliable comparisons, it is crucial to define the breakpoints and the clinical features of each patient. We have identified six patients with DS due to partial trisomy of HSA21, four of them involving only this chromosome. Two of the patients present a translocation involving a partial monosomy of chromosome 13 and 15 respectively; two other patients present a direct duplication from marker D21S302 to the telomere; another patient presents a translocation 21q-21p; finally, we have identified a patient with an interstitial duplication of YAC 876d4 which contains the gene GART. The breakpoints were characterised by FISH using a contig of YACs from 21q previously assessed for chimerism. The clinical evaluation was performed in each case by the clinical geneticists of the referring hospitals, all according to the same protocol. The six patients define four different segmental trisomies: from D21S302 to the telomere, from D21S226 to the telomere, from CBR to the telomere, and finally one case only encompasses the region from D21S216 to D21S323. The clinical comparisons are based, for the traits not fully penetrant, only in the presence of the trait. The results indicate that most of the clinical alterations seen in DS map to the distal third of 21q, as it has already been reported in the literature. Comparing these results with the published ones, it may be concluded that: 1/. The duodenal stenosis may restricted from D21S59 to D21S302; 2/. The furrowed tongue maps from the centromere to D21S323; 3/. Hypotonia may be excluded from the region encompassed from D21S216 to D21S323; 4/: finally, since APP is always excluded from the trisomies studied and two of the patients are older than 30 years and do not show any sign of Alzheimer's like dementia, it may be inferred that trisomy of APP is necessary to develop Alzheimer disease in DS. The characterisation of partial trisomies has enabled the genetic counselling to the families of the patients, specially when the chromosomal rearrangement was of familial origin. We have also applied FISH to map on human chromosomes several genes of HSA21 identified by our Down Syndrome Research Group at the CGMM (IRO). Finally, FISH has been performed to determine the number and chromosomal localisation of transgene insertions of two transgenic mouse models generated in the same lab.
|
3 |
Reabsorció renal d'aminoàcids: anàlisi de mutacions de SLC7A9, el gen de cistinúria de tipus B, i generació d'un model murí "knockout" de Slc7a8Font i Llitjós, Mariona 24 February 2005 (has links)
La cistinúria és una aminoacidúria hereditària autosòmica recessiva (tipus I, OMIM 220100) i dominant amb penetrança incompleta (tipus no I, OMIM 600918) caracteritzada per un defecte en el transport d'aminoàcids bàsics i cistina que afecta les cèl·lules epitelials del túbul renal i de l'intestí. Es manifesta per una hiperaminoacidúria de cistina i aminoàcid dibàsics. La cistina precipita formant càlculs renals que poden produir obstruccions, infeccions i insuficiència renal en alguns casos. S'han descrit tres fenotips: I, no-I i mixte. El 1994 es clonà el cDNA humà de SLC3A1 (que codifica per rBAT), es mapà al cromosoma 2p16, i el nostre grup trobà mutacions en pacients de cistinúria de tipus I. Aquestes mutacions causaven un defecte en el transport quan s'expresaven en oòcits.S'ha acotat el locus de cistinúria de tipus no I al cromosoma 19q13.1, en una zona compresa entre els marcadors C13 i D19S587 de 2,3 Mb. S'ha clonat el gen SLC7A9 que codifica per a la subunitat lleugera de rBAT, b0,+AT. S'ha realitzat un anàlisi exhaustiu de mutacions del gen SLC7A9 en pacients de cistinúria. Aquestes mutacions causen pèrdua de funció del sistema de transport b0,+.El 88% dels al·lels associats al fenotip no I presenten mutacions a SLC7A9 indicant que és el principal responsable del tipus no I. S'han identificat 52 i 24 mutacions noves a SLC7A9 i SLC3A1 en 164 famílies amb cistinúria de l'Internacional Cystinuria Consortium (ICC), que eleven el total de mutacions publicades a 66 i 105 a SLC7A9 i SLC3A1 respectivament.Les mutacions identificades per l'ICC expliquen el 90,5%, 87,6% i 89,3% de pacients amb cistinúria de tipus I, no I i mixt, respectivament. Les mutacions més freqüents de SLC3A1 i SLC7A9 són p.M467T (26,4% dels al·lels mutats) i p.G105R (27,4% dels al·lels mutats) respectivament.L'anàlisi del mRNA de vuit mutacions puntuals de SLC7A9, que no afecten zones consens de splicing, revela que tres d'elles (les freqüents p.R333W i c.614dupA i la rara c.586C>T) presenten alteracions en el splicing. Aquestes mutacions eleven el percentatge d'al·lels amb splicing erroni del 7% al 28%.Per estudis de correlació genotip-fenotip s'ha observat que majoritàriament les mutacions a SLC3A1 i SLC7A9 s'associen a fenotips I i no I respectivament, però aproximadament el 12% dels heterozigots de SLC7A9 presenten fenotip I, i només el 4% dels heterozigots de SLC3A1 (mutació dupE5-E9) presenten fenotip no I. Aquesta dissociació entre genotip i fenotip ha motivat la proposta d'una nova classificació de la cistinúria: tipus A, causat per dues mutacions a SLC3A1; tipus B: causat per dues mutacions a SLC7A9 ; i un possible tipus AB, causat per una mutació a cada un dels gens. Els nostres resultats demostren que l'herència digènica (AB) no dóna lloc a un desenvolupament complet de la malaltia (litiasi), encara que pot agreujar l'hiperexcreció d'aminoàcids.Aproximadament el 13% dels al·lels de pacients amb cistinúria de l'ICC no han estat explicats per mutacions a SLC3A1 o SLC7A9 Aquests al·lels podrien explicar-se per mutacions al promotor o introns, a polimorfismes o a mutacions a altres gens.S'han identificat dos polimorfismes de canvi d'aminoàcid (p.V142A i p.L223M) i tres a la regió promotora de SLC7A9 (c.1-313G>T i c.1-617G>T c.1-1314G>A) que estan associats a cistinúria, suggerint un possible paper d'aquests polimorfismes en la malaltia o l'existència de mutacions associades a aquests encara no identificades. D'altra banda, el polimorfisme IVS8+8C>A en el gen candidat SLC7A8 (LAT-2) sembla que està associat a cistinúria, suggerint un possible paper causatiu o modulador de LAT-2 en el fenotip cistinúric. S'ha descartat la implicació de SLC7A10 (asc-1) en la cistinúria. S'ha començat a generar un ratolí knockout per Slc7a8 (LAT-2) per conèixer el seu possible paper en el fenotip cistinúric i en els altres teixits on s'expressa. / Cystinuria is an autosomal recessive (type I, OMIM 220100) and dominant with low penetrance (type non-I, OMIM 600918) aminoaciduria due to a disorder of renal reabsorption of cystine and dibasic amino acids, which results in urolithiasis of cystine. Three cystinuria phenotypes have been described: I, non-I and mixed. Cystinuria is due to mutations in the heavy subunit rBAT (SLC3A1) and in the light subunit b0,+AT (SLC7A9) of the heteromeric amino acid transporter system b0,+. We narrowed down the locus for type non-I cystinuria on chromosome 19q13.1 to 2,3 Mb, between markers C13 and D19S587. Then cloned SLC7A9, the gene that encodes for the light subunit of rBAT, b0,+AT. We performed an exhaustive mutation analysis of SLC7A9 in cystinuria patients. These mutations caused loss of function of the system b0,+. We have identified 52 new mutations in SLC7A9 and 24 in SLC3A1 from 164 probands that increases the total number of mutations to 66 and 105 respectively. The mutated alleles reached an average of 86.8%. Mutations in SLC3A1 (type A) and in SLC7A9 (type B) accounted for 44.3% and 55.7% of the alleles identified. These data demonstrate that SLC7A9 is the main non-Type I cystinuria gene. The mRNA analysis of eight point mutations in SLC7A9, which do not affect splicing consensus sequences, revealed that three of them showed aberrant splicing. These mutations increase the percentage of alleles with aberrant splicing from 7% to 28%.SLC3A1 heterozygotes showed phenotype I with the exception of some carriers of dupE5-E9, which showed phenotype non-I. SLC7A9 heterozygotes showed phenotype non-I, with the exception of eleven mutations. Therefore we proposed a new cystinuria classification based on genetic criteria: type A caused by two mutations in SLC3A1 (rBAT), type B caused by two mutations in SLC7A9 (bo,+AT) and, the possibility of type AB with one mutation on each of the above genes. Our results indicate that digenic inheritance contributes to the urine phenotype but none of the AB individuals presented cystine urolithiasis. There are still 13% of unexplained alleles. Our results suggest that these alleles may be due to amino acid change polymorphisms and to promoter variants in SLC7A9, rather than to mutations in a third gene.
|
4 |
Transportadores heterométricos de aminoácidos: análisis mutacional de rBAT en cistinuria y estudios de relación estructura-funciónJiménez Vidal, Maite 28 January 2005 (has links)
Los transportadores heteroméricos de aminoácidos (HAT) están formados por una subunidad ligera (LSHAT) y una subunidad pesada (HSHAT) unidas entre ellas mediante un puente disulfuro.Se han descrito dos HSHATs: rBAT, y 4F2hc. Son glicoproteínas de membrana de tipo II, con un extremo N-terminal intracelular, un único dominio trans-membrana y un extremo C-terminal extracelular homólogo a las alfa-amilasas.Hasta el momento se han identificado 9 LSHATS: 6 se unen a 4F2hc para dar lugar al transportador funcional (LAT-1, LAT-2, y+LAT-1, y+LAT-2, asc-1, xCT), una se une a rBAT (bo,+ AT) y existen dos miembros "huérfanos" (asc-2, AGT-1), que no interaccionan con las HSHATs descritas y que quizás se unen a HSHATs todavía por identificar. Las diferentes LSHAT presentan las siguientes características estructurales y funcionales comunes: 1. Son proteínas altamente hidrofóbicas no glicosiladas. 2. Presentan una predicción de estructura de 12 segmentos trans-membrana, con extremos N y C-terminal intracelulares. Esta topología se ha demostrado para la subunidad ligera xCT, que presenta además un reentrant-loop entre los segmentos trans-membrana 2 y 3, con evidencias funcionales de su proximidad a la vía de translocación de sustrato.3. El residuo de cisteína conservado que interviene en la formación del puente disulfuro se encuentra localizado en el dominio extracelular putativo II.4. Necesitan la coexpresión de la HSHAT para alcanzar la membrana plasmática en un sistema de expresión heterólogo. 5. Confieren la especificidad de transporte al complejo heteromérico, representando una gran diversidad de sustratos y acoplamiento a iones: aminoácidos neutros de tamaño grande (LAT-1, LAT-2), pequeño (asc-1, LAT-2), cargados negativamente (xCT) y aminoácidos básicos y neutros (y+LAT-1, y+LAT-2 y bo,+AT).6. Se comportan como intercambiadores obligatorios con una estequiometría 1:1 y con una afinidad intracelular aparente por el sustrato mucho menor que la extracelular, excepto para el caso asc-1/4F2hc, y quizás asc-2, que se comporta como un intercambiador no obligatorio.7. La LSHAT es capaz de mediar el transporte en ausencia de la subunidad pesada cuando se consigue expresarla en superficie, como ocurre en un sistema reconstituido.rBAT (codificada por el gen SLC3A1) y bo,+AT (codificada por el gen SLC7A9) forman el sistema bo,+, que transporta aminoácidos neutros y básicos. Defectos en este sistema de transporte causan cistinuria. La cistinuria (OMIM 220100) es una enfermedad hereditaria, autosómica recesiva, causada por el defecto en la absorción intestinal y la reabsorción renal de aminoácidos básicos (lisina, arginina, ornitina) y cistina. Debido a su baja solubilidad, la cistina precipita formando cálculos a lo largo del sistema urinario. Los cálculos causan obstrucción, infecciones y, en último término, insuficiencia renal. Mutaciones en SLC3A1 causan cistinuria tipo I (recesiva completa: los heterozigotos no presentan hiperexcreción de aminoácidos) y mutaciones en SLC7A9 causan cistinuria tipo no I (recesiva incompleta: los heterozigotos hiperexcretan los cuatro aminoácidos en menor medida que los homozigotos cistinúricos y raramente llegan a desarrollar cálculos).En esta tesis se ha realizado un análisis mutacional de rBAT (SLC3A1) en familias cistinúricas, y estudios de relación estructura-función con las LSHATS bo,+AT y xCT. Debido al solapamiento de fenotipos encontrado en los portadores con mutaciones en SLC3A1 o SLC7A9, se ha establecido una nueva clasificación de la cistinuria, basada en datos genéticos. Los estudios de relación estructura-función han dado lugar a la identificación de un residuo en xCT (C327) próximo al lugar de unión y/o translocación de sustrato, y a la determinación de la unidad funcional mínima en xCT y bo,+AT, formada por una única subunidad ligera. Con estos resultados, y con los conocimientos que tenemos de esta familia de transportadores, proponemos que en una subunidad ligera coexisten dos vías de translocación asimétricas, una para el influjo, y otra para el eflujo. / Heteromeric amino acid transporters (HATs) are composed by disulfide-linked heavy (HSHAT) and light (LSHAT) subunits. HSHATs are type II membrane glycoproteins with a large extracellular domain and are involved in trafficking of the heterodimer to the plasma membrane. The LSHAT is a polytopic membrane protein that confers transport function and specificity. Two HSHATs are known, rBAT and 4F2hc. rBAT forms system b0,+ with the light subunit b0,+AT. 4F2hc forms two different system L isoforms with LAT1 and LAT2, two different system y+L isoforms with y+LAT1 and y+LAT2, system asc with asc1, and system xC- with xCT.Mutations in rBAT (SLC3A1 gene) or b0,+AT (SLC7A9 gene) cause cistinuria, an autosomal inherited metabolic disorder characterised by impaired transport of cystine and dibasic amino acids in the renal tubule and the gastrointestinal tract. High cystine concentration in the urinary tract often causes the formation of cystine stones. SLC3A1 mutations cause type I cystinuria (recessive form) and SLC7A9 mutations cause non-type I cistinuria (dominant form with incomplete penetrance). Mixed cistinuria has also been described. Mutational analysis in SLC3A1 realized in this thesis, together with mutational analysis in SLC7A9 in 164 families of the International Cystinuria Consortium database, established a new genetic classification: type A, with two mutations in SLC3A1; type B, with two mutations in SLC7A9; and type AB, with one mutation on each gene. Digenic inheritance in two mixed families caused partial phenotype.Little is known about the structure-function relationships of the HATs. Structure-function studies realized in this thesis demonstrate that Cys327 in transmembrane domain 8 of xCT is the target for transport inactivation by sulfhydril reagents. Protection and kinetic experiments suggest that Cys327 is close to the substrate permeation pathway. On the other hand, co-injection of xCT or b0,+AT sensitive (wild type) and insensitive (xCT C327S and b0,+AT C321S) to the inactivation by sulfhydryl reagents, and/or the effect of these reagents on concatamers indicate that the heterodimer is the functional unit of systems b0,+ and xc-. Together, with earlier studies on system b0,+, the results suggest that two asymmetric translocation pathways (export and import) co-exist simultaneously on a single LSHAT subunit.
|
5 |
Fenotipske i genotipske karakteristike makrolid rezistentnog Streptococcus pneumoniae / Phenotypic and genotypic characterization of macrolide resistant Streptococcus pneumoniaeHadnađev Mirjana 24 July 2015 (has links)
<p><em>Streptococcus pneumoniae</em> (pneumokok) je jedan od vodećih uzroka morbiditeta i mortaliteta širom sveta, kada su u pitanju infektivne bolesti. Pretežno izaziva infekcije gornjih respiratornih puteva (sinuzitis, otitis) i konjunktivitis. Vodeći je uzročnih vanbolničkih pneumonija, bakterijskog meningitisa i sepse. Lekovi izbora u terapiji pneumokoknih bolesti su beta laktamski antibiotici i makrolidi. Iako se makrolidni antibiotici uveliko koriste u lečenju pneumokoknih infekcija širom sveta, porast rezistencije na makrolide bi mogao da kompromituje njihovu upotrebu. Rezistencija pneumokoka na makrolide je posredovana putem dva glavna mehanizma: modifikacija ciljnog mesta delovanja leka i aktivni efluks leka. Metilaciju 23S ribozomalne ribonukleinske kiseline (rRNK) obavlja enzim metilaza, čiju sintezu kodira<em> ermB</em> gen. Kod ovog tipa rezistencije dolazi do ukrštene rezistencije na makrolide (M), linkozamide (L) i streptogramine B (Sb). Ovakav vid rezistencije se ispoljava kao MLS<sub>b</sub> - fenotip i karakteriše ga visok nivo rezistencije. Može se javiti kao konstitutivni (cMLS) i inducibilni (iMLS). Drugi mehanizam rezistencije na makrolide je aktivni efluks leka, kodiran od strane <em>mefA</em> gena. Efluks antibiotik a determiniše rezistenciju samo na 14-člane i 15-člane makrolide, bez ukrštene rezistencije. Ispoljava se kao M-fenotip, a karakteriše ga niži stepen rezistencije. Cilj ove studije je bio da se odredi u čestalost makrolidne rezistencije <em>Streptococcus pneumoniae</em> među invazivnim i neinvazivnim izolatima kod dece i odraslih, da se odrediti u čestalost korezistencije i multiple rezistencije kod makrolid rezistentnih sojeva <em>Streptococcus pneumoniae</em>, da se fenotipski odredi tip rezistencije na makrolide i da se ispita genska osnova makrolidne rezistencije (detektovati prisustvo <em>ermB</em> i <em>mefA</em> gena). Analizirani su podaci o 326 sojeva <em>Streptococcus pneumoniae</em> rezistentnih na makrolide (MRSP) sakupljenih širom Srbije u periodu od januara 2010. do decembra 2012. godine. Sakupljeni MRSP izolati su transportovani u Nacionalnu referentnu laboratoriju za streptokok radi daljih ispitivanja. Identifikacija je vršena na osnovu mikroskopskih, kulturelnih i biohemijskih osobina. Konzervacija je vršena u moždano-srčanom bujonu sa 10% sadržajem glicerola na -80°C. Dvostruki disk difuzioni test, kombinovani difuzion odilucioni test i automatizovani VITEK 2 sistem su korišćeni za određivanje fenotipova rezistencije na makrolide. Geni koji kodiraju rezistenciju na makrolide su detektovani PCR metodom. Ukupna rezistencija sojeva <em>S.pneumoniae</em> na makrolide u Srbiji je iznosila 34%. Sojevi <em>S.pneumoniae</em> rezistentni na makrolide su češće bili izolovani kod dece (36%) u odnosu na odrasle (29%) osobe, i češće su izolovani iz neinvazivnih (35,5%) u odnosu na invazivne (27,4%) materijale. Dominantan fenotip rezistencije na makrolide je bio MLS<sub>b</sub> fenotip (78,5%). Konstitutivan MLS fenotip je bio zastupljen kod 73,9%, a inducibilan MLS kod 4,6% MRSP izolata. Potvrđena je udruženost <em>mefA</em> gena i M fenotipa; <em>ermB</em> gena i iMLS fenotipa, kao i <em>ermB</em> gena i cMLS fenotipa. Prisustvo oba ermB i mefA gena rezistencije je potvrđeno kod 43,9 % izolata. Svi izolati sa koji su imali oba gena rezistencije su ispoljili MLS<sub>b</sub> fenotip. Istovremena neosetljivost na penicilin je bila zastupljena kod 16% MRSP sojeva. Visok nivo rezistencije na penicilin je imalo svega 5,8% MRSP izolata. Među MRSP sojevima je bio prisutan visok nivo rezistencije na tetraciklin (81,3%) i trimetoprim-sulfametoksazol (74,3%). Multirezistenti sojevi, koji su bili rezistentni na tetracikline i trimetoprim-sulfametoksazol su predstavljali dve trećine (66,1%) MRSP izolata. Zastupljenost udružene rezistencije MRSP na tetraciklin i trimetoprim-sulfametoksazol je bila veća kod sojeva sa MLS fenotipom (73,1%) u odnosu na sojeve sa M fenotipom (36,7%). Zastupljenost istovremene rezistencije na makrolide i druge antibiotike među kojima su penicilin, amoksicilin, cefotaksim, tetraciklin, trimetoprim-sulfametoksazol, kao i multirezistentnih sojeva je bila veća kod pedijatrijskih izolata pneumokoka u odnosu na sojeve dobijene kod odraslih. U čestalost istovremene rezistencije na makrolide i druge antibiotike među kojima su tetraciklin i ofloksacin je bila više prisutna među neinvazivnim u odnosu na invazivne MRSP izolate. Invazivni MRSP izolati iz likvora su pokazivali veću rezistenciju na beta laktamske antibiotike u odnosu neinvazivne sojeve. MRSP sojevi su pokazali veoma visok nivo osetljivosti na levofloksacin (99,6), telitromicin (98,4%), cefotaksim (93,5%), i mipenem (97,3%). MRSP sojevi su u potpunosti bili osetljivi na vankomicin, linezolid, moksifloksacin, sparfloksacin, rifampicin i pristinamicin. Među invazivnim sojevima <em>S.pneumoniae</em> rezistentnim na makrolide je nađeno 12 različitih serotipova. Polovina izolata je pripadala serotipovima 19F (25%) i 14 (23%), dok su sledeći po učestalosti bili 6A (10,4%) i 23F (8,3%). Istovremena rezistencija na makrolide, penicilin, tetracikline i trimetoprim-sulfametoksazol je nađena kod serotipova 19F, 14 i 23F, dok su serotpovi 12F i 31 bili neosetljivi samo na makrolide. Naše istraživanje predstavlja prvu detaljnu analizu fenotipskih i genotipskih osobina sojeva pneumokoka rezistentnih na makrolidne antibiotike u Srbiji. Dobijeni rezultati ukazuju na potrebu za aktivnim nadzorom nad pneumokoknim infekcijama u Srbiji.</p> / <p><em>Streptococcus pneumoniae</em> (pneumococcus) is one of the leading morbidity and mortality causes all over the world with respect to infectious diseases. <em>Streptococcus pneumoniae</em> is a leading cause of upper respiratory tract infections ( sinusitis, otitis) and conjunctivitis. It is also the most common cause of community-acquired pneumonia, bacterial meningitis and sepsis. Beta lactam and macrolide antibiotics remained a first choice for empirical treatment of pneumococcal infections. Although macrolides are widely used for treatment of pneumococcal infections, an increase in macrolide resistance might compromise their use. Pneumococcal macrolide resistance is mediated by two major mechanisms: target site modification and active drug efflux. Methylation of the 23S ribosomal ribonucleic acid (rRNA) is performed by the enzyme methylase, encoded by the<em> ermB </em>gene. Modification of ribosomal targets leads to cross-resistance to macrolides (M), lincosamides (L) and streptogramins B (Sb). It is expressed as the MLS<sub>b</sub> –phenotype, which confers a high-level resistance. This phenotype can be either constitutively (cMLS) or inducibly (iMLS). expressed. Another macrolide resistance mechanism is the active drug efflux, encoded by the <em>mefA </em> gene. The drug efflux confers resistance to 14- and 15-membered macrolides only, with no cross-resistance. It is expressed as the M-phenotype, which confers low-level resistance. The objective of this study was : 1) to examine the prevalence of macrolide resistant <em>Streptococcus pneumoniae </em>(MRSP) among invasive and noninvasive isolates in children and adults, 2) to examine the prevalence of coresistance and multiple-resistance among MRSP strains, 3) to examine the prevalence of macrolide resistant phenotypes, and 4) to examine the prevalence of macrolide resistant genotypes (detect the presence of the <em>ermB</em> and <em>mefA</em> gene). A total of 326 MRSP strains were analyzed, which were collecte dall over Serbia in the period from January, 2010 - December, 2012. The collected MRSP isolates were referred to the National Reference Laboratory for streptococci and pneumococci for further investigation. Identification based on microscopic, culture and biochemical features of the isolates. Conservation was performed in the brain-heart infusion broth with a 10% glycerol content at -80°C. Macrolide resistance phenotypes were determined by a double disc diffusion test, combine d diffusion-dilution test and automatized VITEK 2 system. Macrolide resistance genes were determined by PCR. Overall, macrolide nonsusceptibility rate in Serbia was 34%. MRSP isolates were more prevale nt among children (36%) than adults (29%), and were more prevalent among noninvasive (35.5%) than invasive (27.4%) samples. Predominant macrolide resistance phenotype was the MLS b phenotype (78.5%), from which 73.9 % belonged to cMLS and 4.6% to iMLS phenotype. All the strains assigne d to the MLS<sub>b</sub> phenotype harbored<em> ermB</em> gene, while all the strains with M phenotype had the mefA gene. The presence of both ermB and mefA resistance genes was confirmed in 43.9 % of isolates. All the isolates which harbored both resistance genes expressed the MLS<sub>b</sub> phenotype. Among macrolide resistant strains, penicillin nonsusceptiblility was observed in 16% . A high level resistance was confirmed in 5. 8% of MRSP isolates. MRSP strains showed high resistance rates to tetracyclin (81.3%) and trimethoprim-sulfamethoxazole (74.3%). Multiresistant strains, resistant to tetracyclines and trimethoprim-sulfamethoxazole, made two thirds (66.1 %) of MRSP isolates. Among MRSP, co-resistance to tetracycline and trimethoprim-sulfamethoxazole was more prevalent among MLS phenotypes (73.1%) than M phenotypes (36.7%). Co-resistance strains to macrolides and other antibiotics including penicillin, amoxicillin, cefotaxime, tetracyclin, trimethoprim-sulfamethoxazole and multiresistant strains were more prevalent among children than adult. Coresistance to macrolides and other antibiotics including tetracycline and ofloxacin was more prevalent among noninvasive than invasive strains. Invasive MRSP isolates from the cerebrospinal fluid showed a higher resistance rate to beta lactam antibiotics than noninvasive strains. MRSP strains had a high susceptibility rates to levofloxacin (99.6), telithromycin (98.4%), cefotak sime (93.5%) and imipenem (97.3%). MRSP strains were fully susceptible to vancomycin, linezolid, moxifloxacin, sparfloxacin, rifampicin a nd pristinamycin. Among macrolide resistant <em>S.pneumoniae</em> strains, 12 different serotypes were identified. One half of these isolates belonged to the 19F (27.1%) and 14 (22. 9%) serotype, followed in frequency by the 6A (10.41%) and 23F (8.3%) serotype . Multiresistant strains (macrolides, penicillin, tetracyclines and trimethoprim-sulfamethoxazole) belonged to serotypes 19F, 14 and 23F, while the 12F and 31 serotype were resistant to macrolides only. This in vestigation represents the first detailed analysis of phenotypes and genotypes of macrolide resistant pneumococcal strains in Serbia. The obtained results suggest the need for an active surveillance of pneumococcal infections in Serbia.</p>
|
6 |
Потенцијал за принос и адаптација пшенице на стресне услове солоњеца / Potencijal za prinos i adaptacija pšenice na stresne uslove solonjeca / The Yield Potential of Wheat and Adaptation of Stress Conditions to Solonetz SoilBanjac Borislav 11 September 2015 (has links)
<p>У раду су приказани резултати огледа са једанаест сорти пшенице (Triticum aestivum L.) и једном сортом тритикалеа (Triticosecale W.) на локалитету Кумане у Банату, у стресним условима халоморфног земљишта типа солоњец. Током три вегетационе сезоне је испитана генотипска варијабилност, праћењем фенотипске варијације и интеракције генотип/спољна средина за принос и компоненте приноса (висина биљке, дужина класа, маса класа, маса зрна по класу и број зрна по класу). Оглед је постављен на контролној варијанти (солоњец без поправке) и третманима са мерама поправке, уз примену фосфогипса у количини од 25 t/ha и 50 t/ha. За анализу интеракције генотипа и спољне средине је примењен Модел главних ефеката и вишеструке интеракције-AMMI (Аdditive Мain Еffects and Мultiplicative Interaction). Међузависност испитиваних особина је утврђена анализом једноструких корелација. У циљу дефинисања реакције генотипова на стресне услове солоњеца, испитанa је активност ензимских и неензимских компоненти антиоксидативног система, као и липидне пероксидације.<br />Испољена је статистичка значајност главних ефеката генотипа, агроекосредина и њихове интеракције на варијабилност свих испитиваних својстава. Уочени су генотипови мале интеракције генотип/спољна средина за поједине особине, што би могло да се окарактерише као стабилна реакција тих генотипова у променљивим условима средине, у односу на мелиоративни третман и вегетациону сезону. Корелационом анализом су<br />установљене значајне и високозначајне вредности коефицијената корелације између већине испитиваних својстава. Разлике у активности ензима и неензимских компоненти антиоксидативног система заштите указују да су генотипови различито реаговали на стресне услове солоњеца.<br />Добијени резултати могу да помогну процес стварања генотипова пшенице, који ће да се гаје на земљиштима са вишим концентрацијама натријума и неповољним физичким особинама, са добром стабилношћу.</p> / <p>U radu su prikazani rezultati ogleda sa jedanaest sorti pšenice (Triticum aestivum L.) i jednom sortom tritikalea (Triticosecale W.) na lokalitetu Kumane u Banatu, u stresnim uslovima halomorfnog zemljišta tipa solonjec. Tokom tri vegetacione sezone je ispitana genotipska varijabilnost, praćenjem fenotipske varijacije i interakcije genotip/spoljna sredina za prinos i komponente prinosa (visina biljke, dužina klasa, masa klasa, masa zrna po klasu i broj zrna po klasu). Ogled je postavljen na kontrolnoj varijanti (solonjec bez popravke) i tretmanima sa merama popravke, uz primenu fosfogipsa u količini od 25 t/ha i 50 t/ha. Za analizu interakcije genotipa i spoljne sredine je primenjen Model glavnih efekata i višestruke interakcije-AMMI (Additive Main Effects and Multiplicative Interaction). Međuzavisnost ispitivanih osobina je utvrđena analizom jednostrukih korelacija. U cilju definisanja reakcije genotipova na stresne uslove solonjeca, ispitana je aktivnost enzimskih i neenzimskih komponenti antioksidativnog sistema, kao i lipidne peroksidacije.<br />Ispoljena je statistička značajnost glavnih efekata genotipa, agroekosredina i njihove interakcije na varijabilnost svih ispitivanih svojstava. Uočeni su genotipovi male interakcije genotip/spoljna sredina za pojedine osobine, što bi moglo da se okarakteriše kao stabilna reakcija tih genotipova u promenljivim uslovima sredine, u odnosu na meliorativni tretman i vegetacionu sezonu. Korelacionom analizom su<br />ustanovljene značajne i visokoznačajne vrednosti koeficijenata korelacije između većine ispitivanih svojstava. Razlike u aktivnosti enzima i neenzimskih komponenti antioksidativnog sistema zaštite ukazuju da su genotipovi različito reagovali na stresne uslove solonjeca.<br />Dobijeni rezultati mogu da pomognu proces stvaranja genotipova pšenice, koji će da se gaje na zemljištima sa višim koncentracijama natrijuma i nepovoljnim fizičkim osobinama, sa dobrom stabilnošću.</p> / <p>This paper presents the results of an experiment with eleven varieties of wheat (Triticum aestivum L.) and one triticale variety (Triticosecale W.). The experiment was conducted in stress conditions of the site Kumane in Banat, on solonetz soil. Genotypic variability has been examined, during three growing seasons, through phenotypic variation and genotype/environment interaction for yield and yield components (plant height, spike length, spike weight, seed weight per spike and number of grains per spike). The experiment was set up in the control treatment (solonetz soil without melioration) and the improvement measures with application of phosphogypsum in amount of 25 t/ha and 50 t/ha. The genotype/environment ineraction was analyzed using AMMI model (Additive Main Effect and Multiplicative Interaction). The interrelationship of the studied traits was determined by the single correlation coefficients. In order to define the genotype response to stress of solonetz, the activity of enzimatic and non-enzimatic antioxidant system and lipid peroxidation were examined.<br />The statistical significance of the main effects of genotypes, environments and their interaction on variation of all the traits was observed. The observed genotypes with low genotype/environment interaction for certain traits, which could be characterized as a stable reaction of these genotypes in variable environmental conditions, in relation to the ameliorated measures and growin seson. For the different traits as the most stable ones, various genotypes were obtained. The genotypes in study reacted differently to different levels of melioration, in relation to each treatment<br />and growing season. Correlation analysis were established significant and highly significant values of correlation coefficients between the most of studied traits. Differences in the activity of enzymatic and non-enzymatic components of the antioxidant protection suggests that the genotypes responded differently to stress conditions of solonetz.<br />The results can help the process of creating wheat genotypes, which will be grown on soils with higher concentrations of sodium and unfavorable physical properties, which would have good stability.</p>
|
7 |
Espectro clínico-mutacional y estudios de correlación genotipo-fenotipo en la población española afectada de lipofuscinosis neuronal ceroideaPérez Poyato, María del Socorro 02 July 2012 (has links)
Las lipofuscinosis neuronal ceroidea (LNCs) constituyen uno de los grupos de enfermedades neurodegenerativas de herencia autosómica recesiva más frecuentes en la infancia. Presentan variabilidad en la edad de inicio y comparten amplio espectro fenotípico: epilepsia, déficit visual, deterioro motor y cognitivo progresivos con fallecimiento a edad precoz. Se han identificado ocho genes responsables de las diferentes formas clínicas en la edad pediátrica (CLN10/CTSD, CLN1/PPT1, CLN2/TPP1, CLN3, CLN5, CLN6, CLN7/MFSD8 y CLN8). El análisis mutacional permite asociar el defecto genético a cada una de las formas clínicas: congénita, LNCC (CLN10); infantil, LNCI (CLN1); infantil tardía, LNCIT (CLN2); juvenil, LNCJ (CLN3); variante infantil tardía finlandesa, vLNCITFin (CLN5); variante infantil tardía juvenil precoz, vLNCITJuv (CLN6); variante infantil tardía turca, vLNCITTur (CLN7) y variante infantil tardía epilepsia del norte con retraso mental, EPMR - variante infantil tardía (CLN8).
Nos proponemos, a través de los estudios realizados en los pacientes españoles con LNC, profundizar en el conocimiento de los aspectos clínicos y moleculares de este grupo de enfermedades, determinar el espectro mutacional de los genes CLN1, CLN2, CLN3, CLN5 y CLN7 y establecer una adecuada correlación genotipo-fenotipo en la población pediátrica de nuestro país.
Desde el año 1974-2011 se estudiaron 6 pacientes con LNCI (5 núcleos familiares). Desde el año 1979-2011 se estudiaron 12 pacientes con LNCIT (10 núcleos familiares). Desde el año 1975-2010 se estudiaron 24 pacientes con LNCJ, divididos en 2 grupos: variante (11 pacientes) con mutaciones en el gen CLN1 y clásico (13 pacientes) con mutaciones en el gen CLN3. Se describieron 3 pacientes con vLNCITFin y uno con vLNCITTur. Se creó una base de datos clínica con 50 ítems. Para el estudio estadístico se utilizó la prueba de Kaplan-Meier.
Los pacientes con LNCI, iniciaron la enfermedad entre los 8-15 meses con retraso en el desarrollo motor y marcha inestable. La epilepsia puede aparecer en cualquier momento. La LNCI se caracteriza por un severo y progresivo curso clínico y en nuestra población, la mutación V181M en el gen CLN1 está asociada con el fenotipo más severo de la enfermedad.
La LNCIT se inició entre los 18 meses y los 3.7 años con retraso del lenguaje y convulsiones febriles simples seguidas de epilepsia. El trastorno de aprendizaje y la ataxia ocurrieron a los 4 años. La regresión clínica se inició con una pérdida de las frases, seguido de pérdida de la deambulación. Todos los pacientes desarrollaron epilepsia mioclónica continua. La LNCIT presenta un curso clínico muy homogéneo y se demuestra heterogeneidad genética en nuestra población.
La forma variante de LNCJ se inició con retraso / regresión del lenguaje y dificultades de aprendizaje mientras que la forma clásica se inició con déficit visual. La regresión clínica se inició con una pérdida de las frases seguida por una pérdida de la deambulación durante la adolescencia en el grupo variante y durante la edad adulta el grupo clásico. El curso clínico es más severo y progresivo en pacientes con mutaciones en el gen CLN1 que en el gen CLN3. La mutación V181L en el gen CLN1 fue identificada en homocigosis en 9 pacientes pertenecientes a 4 familias consanguíneas, no relacionadas, todas de etnia gitana. Se considera la posibilidad de realizar un diagnóstico precoz de LNCJ en base a la sintomatología inicial y la edad de inicio. El índice de progresión de la enfermedad orienta hacia los fenotipos causados por mutaciones en los genes CLN1 / CLN3 y el diagnóstico definitivo deberá confirmarse mediante el análisis mutacional de dichos genes.
Se ha elaborado un protocolo diagnóstico que permite realizar estudios de correlación genotipo-fenotipo y amplía el espectro clínico-mutacional en la población española afectada de lipofuscinosis neuronal ceroidea. / Neuronal ceroid lipofuscinosis (NCLs) is one of the most common groups of progressive neurodegenerative diseases in childhood. Eight disease genes causing NCL in childhood have been identified: CLN10/CTSD, CLN1/PPT1, CLN2/TPP1, CLN3, CLN5, CLN6, CLN7/MFSD8, and CLN8.
The main objective was to assess the natural history of the disease and to establish phenotype/genotype correlations in Spanish patients with NCL.
Infantile neuronal ceroid lipofuscinosis (INCL) is caused by mutations in the CLN1/PPT gene. The age at disease onset in six Spanish patients with INCL ranged from 8 to 15 months. Delayed motor skills and ataxia were the initial symptoms. The V181M mutation in the CLN1 gene was found in homozygosis which is associated with the most severe INCL phenotype.
Late infantile neuronal ceroid lipofuscinosis (LINCL) is caused by mutations in the CLN2. The clinical outcome in 12 Spanish patients reported the age at onset of clinical symptoms ranged from 18 months to 3.7 years, and they included delayed speech and simple febrile seizures followed by epilepsy. Clinical regression was initiated by loss of sentences followed by loss of walking ability. The clinical progression of LINCL was relatively homogeneous and genetic heterogeneity was demonstrated in the 10 families studied.
Juvenile neuronal ceroid lipofuscinosis (JNCL) is usually caused by a 1.02-kb deletion in the CLN3 gene and mutations in the CLN1 gene may be associated with a variant form of JNCL (vJNCL). To assess the natural history of the disease, 24 Spanish patients with JNCL were studied. Patients were classified into the groups of vJNCL with mutations in the CLN1 gene (n= 11) and classic JNCL (cJNCL) with mutations in the CLN3 gene (n=13). Patients with vJNCL showed a more severe and progressive clinical course than those with cJNCL. The rate of disease progression may be useful to diagnose vJNCL or cJNCL, which should be confirmed by molecular studies in CLN1/CLN3 genes.
Three unrelated patients with Finnish variant late infantile (CLN5) and another patient with Turkish variant late infantile (CLN7) were described.
The diagnostic algorithm is a useful tool for the diagnosis of the patients with NCL and the correlation genotype-phenotype studies in Spain.
|
Page generated in 0.0512 seconds