21 resultados para Phenotypic markers
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
Selostus: RAPD- ja RFLP-markkereista koostuva rypsin kytkentäkartta
Resumo:
Abstract
Resumo:
Selostus: Ponsiviljeltävyys ja siihen liittyvät geenimerkit peltokauran ja susikauran risteytysjälkeläisissä
Resumo:
Background: Measurement of serum cotinine, a major metabolite of nicotine, provides a valid marker for quantifying exposure to tobacco smoke. Exposure to tobacco smoke causes vascular damage by multiple mechanisms, and it has been acknowledged as a risk factor for atherosclerosis. Multifactorial atherosclerosis begins in childhood, but the relationship between exposure to tobacco smoke and arterial changes related to early atherosclerosis have not been studied in children. Aims: The aim of the present study was to evaluate exposure to tobacco smoke with a biomarker, serum cotinine concentration, and its associations with markers of subclinical atherosclerosis and lipid profile in school-aged children and adolescents. Subjects and Methods: Serum cotinine concentration was measured using a gas chromatographic method annually between the ages 8 and 13 years in 538-625 children participating since infancy in a randomized, prospective atherosclerosis prevention trial STRIP (Special Turku coronary Risk factor Intervention Project). Conventional atherosclerosis risk factors were measured repeatedly. Vascular ultrasound studies were performed among 402 healthy 11-year-old children and among 494 adolescents aged 13 years. Results: According to serum cotinine measurements, a notable number of the school aged children and adolescents were exposed to tobacco smoke, but the exposure levels were only moderate. Exposure to tobacco smoke was associated with decreased endothelial function as measured with flow-mediated dilation of the brachial artery, decreased elasticity of the aorta, and increased carotid and aortic intima-media thickness. Longitudinal exposure to tobacco smoke was also related with increased apolipoprotein B and triglyceride levels in 13-year-old adolescents, whose body mass index and nutrient intakes did not differ. Conclusions: These findings suggest that exposure to tobacco smoke in childhood may play a significant role in the development of early atherosclerosis. Key Words: arterial elasticity, atherosclerosis, children, cotinine, endothelial function, environmental tobacco smoke, intima-media thickness, risk factors, ultrasound
Resumo:
Hormone-dependent diseases, e.g. cancers, rank high in mortality in the modern world, and thus, there is an urgent need for new drugs to treat these diseases. Although the diseases are clearly hormone-dependent, changes in circulating hormone concentrations do not explain all the pathological processes observed in the diseased tissues. A more inclusive explanation is provided by intracrinology – a regulation of hormone concentrations at the target tissue level. This is mediated by the expression of a pattern of steroid-activating and -inactivating enzymes in steroid target tissues, thus enabling a concentration gradient between the blood circulation and the tissue. Hydroxysteroid (17beta) dehydrogenases (HSD17Bs) form a family of enzymes that catalyze the conversion between low active 17-ketosteroids and highly active 17beta-hydroxysteroids. HSD17B1 converts low active estrogen (E1) to highly active estradiol (E2) with high catalytic efficiency, and altered HSD17B1 expression has been associated with several hormone-dependent diseases, including breast cancer, endometriosis, endometrial hyperplasia and cancer, and ovarian epithelial cancer. Because of its putative role in E2 biosynthesis in ovaries and peripheral target tissues, HSD17B1 is considered to be a promising drug target for estrogen-dependent diseases. A few studies have indicated that the enzyme also has androgenic activity, but they have been ignored. In the present study, transgenic mice overexpressing human HSD17B1 (HSD17B1TG mice) were used to study the effects of the enzyme in vivo. Firstly, the substrate specificity of human HSD17B1 was determined in vivo. The results indicated that human HSD17B1 has significant androgenic activity in female mice in vivo, which resulted in increased fetal testosterone concentration and female disorder of sexual development appearing as masculinized phenotype (increased anogenital distance, lack of nipples, lack of vaginal opening, combination of vagina with urethra, enlarged Wolffian duct remnants in the mesovarium and enlarged female prostate). Fetal androgen exposure has been linked to polycystic ovary syndrome (PCOS) and metabolic syndrome during adulthood in experimental animals and humans, but the genes involved in PCOS are largely unknown. A putative mechanism to accumulate androgens during fetal life by HSD17B1 overexpression was shown in the present study. Furthermore, as a result of prenatal androgen exposure locally in the ovaries, HSD17B1TG females developed ovarian benign serous cystadenomas in adulthood. These benign lesions are precursors of low-grade ovarian serous tumors. Ovarian cancer ranks fifth in mortality of all female cancers in Finland, and most of the ovarian cancers arise from the surface epithelium. The formation of the lesions was prevented by prenatal antiandrogen treatment and by transplanting wild type (WT) ovaries prepubertally into HSD17B1TG females. The results obtained in our non-clinical TG mouse model, together with a literature analysis, suggest that HSD17B1 has a role in ovarian epithelial carcinogenesis, and especially in the development of serous tumors. The role of androgens in ovarian carcinogenesis is considered controversial, but the present study provides further evidence for the androgen hypothesis. Moreover, it directly links HSD17B1-induced prenatal androgen exposure to ovarian epithelial carcinogenesis in mice. As expected, significant estrogenic activity was also detected for human HSD17B1. HSD17B1TG mice had enhanced peripheral conversion of E1 to E2 in a variety of target tissues, including the uterus. Furthermore, this activity was significantly decreased by treatments with specific HSD17B1 inhibitors. As a result, several estrogen-dependent disorders were found in HSD17B1TG females. Here we report that HSD17B1TG mice invariably developed endometrial hyperplasia and failed to ovulate in adulthood. As in humans, endometrial hyperplasia in HSD17B1TG females was reversible upon ovulation induction, triggering a rise in circulating progesterone levels, and in response to exogenous progestins. Remarkably, treatment with a HSD17B1 inhibitor failed to restore ovulation, yet completely reversed the hyperplastic morphology of epithelial cells in the glandular compartment. We also demonstrate that HSD17B1 is expressed in normal human endometrium, hyperplasia, and cancer. Collectively, our non-clinical data and literature analysis suggest that HSD17B1 inhibition could be one of several possible approaches to decrease endometrial estrogen production in endometrial hyperplasia and cancer. HSD17B1 expression has been found in bones of humans and rats. The non-clinical data in the present study suggest that human HSD17B1 is likely to have an important role in the regulation of bone formation, strength and length during reproductive years in female mice. Bone density in HSD17B1TG females was highly increased in femurs, but in lesser amounts also in tibias. Especially the tibia growth plate, but not other regions of bone, was susceptible to respond to HSD17B1 inhibition by increasing bone length, whereas the inhibitors did not affect bone density. Therefore, HSD17B1 inhibitors could be safer than aromatase inhibitors in regard to bone in the treatment of breast cancer and endometriosis. Furthermore, diseases related to improper growth, are a promising new indication for HSD17B1 inhibitors.
Resumo:
Oral lichen planus (OLP) is a chronic inflammatory mucosal disease and is detected in between 0.5% - 2.2% of the population. WHO has defined OLP as a potentially precancerous disorder, representing a generalized state associated with a significantly increased risk of cancer. However, only 0.5 – 2.9% of OLP lesions will progress to cancer. Currently, there are no prognostic markers to identify the lesions at increased risk for malignant transformation. The main aim of these studies was to identify cellular and molecular markers in order to understand the pathogenesis of atrophic OLP and its progression towards malignancy. Selected markers for cell proliferation, adhesion, apoptosis, and lymphocytic infiltration were assessed by immunohistochemistry in addition to static cytometry analyses for DNA content. DNA quantification of epithelial cells in 82 biopsy samples derived from atrophic lichen planus showed altered DNA content in 41% of the samples. DNA content was associated with proliferation activity, topoisomerase IIalpha, desmocollin-1 and infection with human papillomavirus. CD27+ and CD38+ lymphocytes were detected in inflammatory cell infiltrate, indicating an abnormal homing of B cells from blood circulation to tissue. Physiologic cell death, apoptosis, is frequently seen in OLP, but its pathways are unknown. Here it was shown that caspases 2 and 12 were up-regulated in OLP, indicating that intracellular apoptosis, rather than an external causal factor, is triggering apoptosis. However, this thesis could not identify any singular prognostic marker of malignancy in OLP. Thus, every OLP patient should receive regular follow-up care to identify cancer risk patients at an early stage.
Resumo:
Molekyylimarkkerit ja pitkäaikainen alfainterferonihoito munuaissyövässä Munuaissyöpäpotilaiden viiden vuoden elossaololuku on noin 50 %. Aikaisempien tutkimuksien mukaan viiden vuoden elossaololuku metastasoituneessa munuaissyövässä on 3-16 %, kun käytettiin alfainterferonia sisältävää hoitoa. Tyypillisesti alfainterferonia on käytetty vähemmäin kuin 6 kuukautta. Avoimia kysymyksiä ovat alfainterferonin optimaalinen hoitoannos ja hoidon kesto yksin tai yhdessä uusien täsmähoitojen kanssa. Tärkeimmät tavoitteet olivat tutkia 1) jaksotetun pitkäaikaisen alfainterferonihoidon tehoa ja siedettävyyttä metastasoituneessa munuaissyövässä ja 2) p53-, Ki-67- ja COX-2-proteiinituotannon ennusteellista merkitystä munuaissyövässä. Tutkimuksessa 117 metastasoituneelle munuaissyöpää sairastaneelle potilaalle etsittiin yksilöllinen hänen sietämänsä maksimaalinen hoitoannos rekombinanttia alfa2a-interferonia (Roferon-ATM). Hoitoa pyrittiin jatkamaan 24 kuukauden ajan. Kolmen hoitoviikon jälkeen pidettiin yhden viikon tauko. Hoito lopetettiin, jos ilmaantui vakavia haittavaikutuksia tai tauti eteni. Toisessa tutkimuksessa proteiinituotanto analysoitiin immunohistokemiallisesti munuaissyöpäpotilaiden kasvainnäytteistä, joita oli säilytetty parafiinissa. Kasvainnäytteet oli otettu talteen munuaisen poistoleikkauksen yhteydessä. Nämä potilaat jaettiin kolmeen eri ryhmään: metastasointi primaarivaiheessa (n=29), metastasointi myöhemmin (n=37) ja ei metastasointia (n=51). Keskimääräinen alfainterferonihoidon kesto oli 11 kuukautta (kk) [0,5 – 32 kk]. Objektiivinen hoitovaste todettiin 17 %:lla, tautitilanne pysyi ennallaan 42 %:lla ja myöhäinen vaste (yli 12 kk:tta hoidon aloittamisesta) todettiin 3 %:lla. Aika vasteen saavuttamisesta taudin etenemiseen oli keskimäärin 8 kk ja elinaika 19,1 kk. Viiden vuoden elossaololuku oli 16 %. Jos metastasoituneella munuaissyöpäpotilaalla oli keuhkometastasointi, hän selvisi todennäköisemmin viisi vuotta kuin muut potilaat. Henkeä uhkaavia sivuvaikutuksia ei todettu. Yli 12 kk:n ajan kestävä alfainterferonihoito on hyödyllistä niille potilaille, jotka ovat saaneet objektiivisen hoitovasteen tai tautitilanne on pysynyt ennallaan. Positiivinen p53- ja Ki-67-ekspressio yhdessä viittaavat suureen metastasoinnin todennäköisyyteen. Positiivinen COX-2-ekspressio viittaa viivästyneeseen metastaasien ilmaantumiseen. Metastasoituneilla potilailla positiiviset p53- ja Ki-67-ekspressiot viittaavat huonoon ennusteeseen, mutta positiivinen COX-2 ekspressio viittaa suotuisaan ennusteeseen. Positiivinen COX-2- ja negatiivinen Ki-67-ekspressio yhdessä viittaavat parantuneeseen ennusteeseen metastasoituneessa munuaissyövässä.
Resumo:
A common feature of natural populations is that individuals differ in morphology, physiologyand behavior (i.e .phenotype). A thorough understanding of the molecular mechanisms and evolutionary forces behind this phenotypic variation is a prerequisite for understanding evolution.This thesis examines the molecular mechanism and the roles of the different evolutionary forces in plumage colour variation in pied flycatchers (Ficedulahypoleuca). Malepied flycatchers exhibit marked variation in both pigmentary and structural plumage colourand the trait has repeatedly been suggested to be of adaptive significance. An examination of plumage colour variation on reproductive output trevealed that structural colouration, and more specifically the degree of ultraviolet (UV) reflectance had an effect on number of young sired. Paternity analyses of breeding males revealed that males that had been cuckolded by their social mate tended to be less UV reflectant than males that had not been cuckolded.Neither pigment-based norstructural colouration was found to affect the probability of siring young in other nests. Phenotypic differentiation was found to be markedly greater than differentiation at neutralgenetic markers across the pied flycatcher breeding range. Furthermore patterns of differentiationin phenotypes and selectively neutral genes were not uniform. Outlier tests searching for genomic footprints of selection revealed elevated levels of genetic divergence in a gene associated with feather development (and thus potentially structural colouration) and ultraviolet vision. Th eobserved differentiation in allelic frequencies was particularly pronounced in the Spanish piedflycatcher populations. Examining gene expression during feather development indicated that the TYRP1 gene (known to be involved in the production of black pigment) may be relevant in generating phenotypic variation in pied flycatcher plumage. Also, energy homeostasis related genesfeatured prominently among the genes found to be expressed in one extreme phenotype but not the other. This is of particular interest in light of what is known about the pleiotropy ofthe melanocortin system which underlies brown-black pigment production. The melanocortinsystem is also associated with energy homeostasis (among a number of other physiological functions) and thus the results could be pointing to the signalling function of brown-blackplumage. Plumage colour variation in pied flycatchers, both structural and pigmentary, can thus beconcluded to be exhibiting signals of non-neutral evolution. Structural colouration was found to play a role in sexual selection and putative signals of selection were further detected in acandidate gene for this trait. Evidence for non-neutral evolution of pigmentary colouration was also detected. These findings, together with the fact that preliminary evidence for an energy balance associated signalling function for plumage was found, present good starting points for further investigations into the meaning and mechanisms of plumage colour variation in piedflycatchers.
Resumo:
Incidence of nonmelanoma skin cancer (NMSC) is increasing. Ultraviolet (UV) –light is a major risk factor for the development of cutaneous SCC. Cutaneous SCCs that develop to chronic ulcers are known to progress and metastasize more easily than UV-induced SCCs. Matrix metalloproteinases (MMPs) are a group of proteolytic enzymes which are suggested to have a role in cancer growth and invasion. The molecular background for progression of cutaneous SCC was examined by immunohistochemistry (IHC) using tissue samples of recessive dystrophic epidermolysis bullosa (RDEB) –associated SCC, sporadic UV-induced SCC, and SCC precursors. IHC studies using tissue microarray (TMA) technique revealed overexpression of MMP-7 and MMP-13 in SCC tumor cells. MMP-7 expression was enhanced especially in the SCC tumor cells of the RDEB –associated SCCs. Studies with SCC cell lines showed that tumor cell derived MMP-7 activated heparin binding epidermal growth factor –like growth factor (HB-EGF) which enhanced the growth of SCC tumor cells. Further, it was shown that type VII collagen (COL7) is expressed in sporadic SCC tumor cells. Interestingly, it was shown that SCC –associated MMP-13 is capable of cleaving COL7 in vitro. COL7 cleavage may have a role in the progression of cutaneous SCC. Studies on serine proteinase inhibitor gene family using SCC tumor cell gene array, quantitative real-time PCR, SCC cell lines, normal human epidermal keratinocytes and IHC of TMA samples showed that serine proteinase inhibitor clade A, member 1 (serpinA1, alpha-1-antitrypsin) is expressed and produced by human SCC tumor cells but not by normal keratinocytes. Moreover, serpinA1 expression was shown to correlate with the progression of cutaneous SCC using transformed HaCaT-cell lines and mouse chemically induced skin SCC model. SerpinA1 may serve as a novel biomarker for the progression of cutaneous SCC. This study elucidated putative mechanisms of the progression of cutaneous SCC and revealed novel biomarker candidates for the progression of SCC of the skin.
Resumo:
Ett element som har intresserat forskarna av fornengelska sedan början av filologiska studier är adverbet þa ’då’, som är högfrekvent i många berättande texter. Utöver ordföjldsregeln enligt vilken satsinitialt þa följs av omvänd ordföljd, finns det redan tidigt kommentarer om användningen av þa för emfas, livlighet och konnektivitet. Även om sådana karakteriseringar tar den textuella kontexten i beaktande, är deras fokus inte på diskursfunktioner utan på satsgrammatik. Denna avhandling betraktar användningen av þa från diskursstrukturens perspektiv och undersöker dess funktioner i markeringen av berättelsens huvudlinje (eng. grounding), kohesiva kontinuiter (eng. continuities), samt vändpunkter och spänning (eng. peak, tension) i texten. I stället för att fokusera på bara en funktion som har associerats med þa, undersöks denna frekventa element från olika perspektiv. Genom både kvantitativa och kvalitativa analyser av narrativt material, visar de inkluderade delstudierna att detta ord spelar en viktig roll i struktureringen av fornengelska berättelser. Parallellt med kärnfunktionen att markera berättelsens huvudlinje, används þa i samspel med andra strukturerande element för att uttrycka den hierarkiska strukturen och spänning i berättelsen. Jämförelser med andra uttryck av temporal kontinuitet visar att þa skiljer sig från dem i sina användningsmönster, vilket vidare bekräftar dess status som en narrativ diskursmarkör.