Cytotoxic, mutagenic and carcinogenic properties of ultraviolet radiation : shining light on photolesions

Exposure to ultraviolet light (UV light) poses a serieus threat to human health. An altered life style (holidays in the sun, tanning devices) has led to increased exposure to UV light in the Western population. UV light damages the DNA, the carrier of genetic information, which can result in permanent alterations in the genome and, ultimately, cancer. The majority of the DNA lesions induced by UV light consists of cyclobutane pyrimidine dimers (CPDs) and pyrimidine-(6,4)-pyrimidone photoproducts (6-4PPs). The relative contribution of these CPDs and 6-4PPs to the effects of acute and chronic UV exposure, however, is nat known (e.g. sunburn, cancer). Although organisms are equipped with the nucleotide excision repair (NER) mechanism for remaval of lesions, this mechanism may nat offer sufficient proteetion in cases of excessive exposure to UV light. The aim of this thesis is to further elucidate the mechanisms behind the detrimental effects of UV exposure and to determine the role of individual classes of UV-induced DNA lesions in these processes. To this end, we generated mice transgenically expressing photolyase enzymes. This approach enables light-controlled remaval of a single type of lesion, allowing investigation of the contribution of individual lesions to UV responses. In Chapter 1, we review the current knowledge on UV-induced DNA damage and repair, and the consequences of UV exposure on human health. Chapters 2 and 3 describe the generation of ubiquitously expressing CPD and 6-4PP photolyase transgenie mice. We show that these marsupial and plant photolyase gene products are functional in mice, resulting in light-dependent remaval of DNA lesions from mouse skin. Furthermore, we provide evidence that CPDs are responsible for adverse UV effects including cell death, sunburn and permanent genomic alterations (mutations). In Chapter 4 we describe the generation of transgenie mice expressing photolyase from the keratinocyte-specific K14 promoter, allowing fast remaval of DNA damage by photoreactivation in basal keratinocytes of the epidermis, whereas in other cell types such as fibroblasts and Langerhans cells lesions are repaired in slow fashion (if at all). This gave us the unique opportunity to dissect the cell types involved in UV responses. In Chapter 5 the carcinogenic potentia

Is a motivational interviewing based lifestyle intervention for obese pregnant women across Europe implemented as planned? Process evaluation of the DALI study

Background: Process evaluation is an essential part of designing and assessing complex interventions. The vitamin D and lifestyle intervention study (DALI) study is testing different strategies to prevent development of gestational diabetes mellitus among European obese pregnant women with a body mass index ≥29kg/m2. The intervention includes guidance on physical activity and/or healthy eating by a lifestyle coach trained in motivational interviewing (MI). The aim of this study was to assess the process elements: reach, dose delivered, fidelity and satisfaction and to investigate whether these process elements were associated with changes in gestational weight gain (GWG). Methods: Data on reach, dose delivered, fidelity, and satisfaction among 144 participants were collected. Weekly recruitment reports, notes from meetings, coach logs and evaluation questionnaires (n=110) were consulted. Fidelity of eight (out of twelve) lifestyle coach practitioners was assessed by analysing audio recorded counselling sessions using the MI treatment integrity scale. Furthermore, associations between process elements and GWG were assessed with linear regression analyses. Results: A total of 20% of the possible study population (reach) was included in this analysis. On average 4.0 (of the intended 5) face-to-face sessions were delivered. Mean MI fidelity almost reached \u27expert opinion\u27 threshold for the global scores, but was below \u27beginning proficiency\u27 for the behavioural counts. High variability in quality of MI between practitioners was identified. Participants were highly satisfied with the intervention, the lifestyle coach and the intervention materials. No significant associations were found between process elements and GWG. Conclusion: Overall, the intervention was well delivered and received by the study population, but did not comply with all the principles of MI. Ensuring audio recording of lifestyle sessions throughout the study would facilitate provision of individualized feedback to improve MI skills. A larger sample size is needed to confirm the lack of association between process elements and GWG. Trial registration: ISRCTN registry: ISRCTN70595832 ; Registered 12 December 2011

Powerful Skin Cancer Protection by a CPD-Photolyase Transgene

AbstractBackground: The high and steadily increasing incidence of ultraviolet-B (UV-B)-induced skin cancer is a problem recognized worldwide. UV introduces different types of damage into the DNA, notably cyclobutane pyrimidine dimers (CPDs) and (6-4) photoproducts (6-4PPs). If unrepaired, these photolesions can give rise to cell death, mutation induction, and onset of carcinogenic events, but the relative contribution of CPDs and 6-4PPs to these biological consequences of UV exposure is hardly known. Because placental mammals have undergone an evolutionary loss of photolyases, repair enzymes that directly split CPDs and 6-4PPs into the respective monomers in a light-dependent and lesion-specific manner, they can only repair UV-induced DNA damage by the elaborate nucleotide excision repair pathway.Results: To assess the relative contribution of CPDs and 6-4PPs to the detrimental effects of UV light, we generated transgenic mice that ubiquitously express CPD-photolyase, 6-4PP-photolyase, or both, thereby allowing rapid light-dependent repair of CPDs and/or 6-4PPs in the skin. We show that the vast majority of (semi)acute responses in the UV-exposed skin (i.e., sunburn, apoptosis, hyperplasia, and mutation induction) can be ascribed to CPDs. Moreover, CPD-photolyase mice, in contrast to 6-4PP-photolyase mice, exhibit superior resistance to sunlight-induced tumorigenesis.Conclusions: Our data unequivocally identify CPDs as the principal cause of nonmelanoma skin cancer and provide genetic evidence that CPD-photolyase enzymes can be employed as effective tools to combat skin cancer

The potential and limitations of intrahepatic cholangiocyte organoids to study inborn errors of metabolism

Inborn errors of metabolism (IEMs) comprise a diverse group of individually rare monogenic disorders that affect metabolic pathways. Mutations lead to enzymatic deficiency or dysfunction, which results in intermediate metabolite accumulation or deficit leading to disease phenotypes. Currently, treatment options for many IEMs are insufficient. Rarity of individual IEMs hampers therapy development and phenotypic and genetic heterogeneity suggest beneficial effects of personalized approaches. Recently, cultures of patient-own liver-derived intrahepatic cholangiocyte organoids (ICOs) have been established. Since most metabolic genes are expressed in the liver, patient-derived ICOs represent exciting possibilities for in vitro modeling and personalized drug testing for IEMs. However, the exact application range of ICOs remains unclear. To address this, we examined which metabolic pathways can be studied with ICOs and what the potential and limitations of patient-derived ICOs are to model metabolic functions. We present functional assays in patient ICOs with defects in branched-chain amino acid metabolism (methylmalonic acidemia), copper metabolism (Wilson disease), and transporter defects (cystic fibrosis). We discuss the broad range of functional assays that can be applied to ICOs, but also address the limitations of these patient-specific cell models. In doing so, we aim to guide the selection of the appropriate cell model for studies of a specific disease or metabolic process

Active vitamin D (1,25-dihydroxyvitamin D) and bone health in middle-aged and elderly men: the European male aging study (EMAS)

<p>Context: There is little information on the potential impact of serum 1,25-dihydroxyvitamin D [1,25(OH)2D] on bone health including turnover.</p> <p>Objective: The objective of the study was to determine the influence of 1,25(OH)2D and 25-hydroxyvitamin D [25(OH)D] on bone health in middle-aged and older European men.</p> <p>Design, Setting, and Participants: Men aged 40–79 years were recruited from population registers in 8 European centers. Subjects completed questionnaires that included questions concerning lifestyle and were invited to attend for quantitative ultrasound (QUS) of the heel, assessment of height and weight, and a fasting blood sample from which 1,25(OH)2D, 25(OH)D, and PTH were measured. 1,25(OH)2D was measured using liquid chromatography tandem mass spectrometry. Bone markers serum N-terminal propeptide of type 1 procollagen (P1NP) and crosslinks (β-cTX) were also measured. Dual-energy x-ray absorptiometry (DXA) of the hip and lumbar spine was performed in 2 centers.</p> <p>Main Outcome Measure(s): QUS of the heel, bone markers P1NP and β-cTX, and DXA of the hip and lumbar spine were measured.</p> <p>Results: A total of 2783 men, mean age 60.0 years (SD 11.0) were included in the analysis. After adjustment for age and center, 1,25(OH)2D was positively associated with 25(OH)D but not with PTH. 25(OH)D was negatively associated with PTH. After adjustment for age, center, height, weight, lifestyle factors, and season, 1,25(OH)2D was associated negatively with QUS and DXA parameters and associated positively with β-cTX. 1,25(OH)2D was not correlated with P1NP. 25(OH)D was positively associated with the QUS and DXA parameters but not related to either bone turnover marker. Subjects with both high 1,25(OH)2D (upper tertile) and low 25(OH)D (lower tertile) had the lowest QUS and DXA parameters and the highest β-cTX levels.</p> <p>Conclusions: Serum 1,25(OH)2D is associated with higher bone turnover and poorer bone health despite being positively related to 25(OH)D. A combination of high 1,25(OH)2D and low 25(OH)D is associated with the poorest bone health.</p&gt

Active vitamin D (1,25-dihydroxyvitamin D) and bone health in middle-aged and elderly men: the European male aging study (EMAS)

<p>Context: There is little information on the potential impact of serum 1,25-dihydroxyvitamin D [1,25(OH)2D] on bone health including turnover.</p> <p>Objective: The objective of the study was to determine the influence of 1,25(OH)2D and 25-hydroxyvitamin D [25(OH)D] on bone health in middle-aged and older European men.</p> <p>Design, Setting, and Participants: Men aged 40–79 years were recruited from population registers in 8 European centers. Subjects completed questionnaires that included questions concerning lifestyle and were invited to attend for quantitative ultrasound (QUS) of the heel, assessment of height and weight, and a fasting blood sample from which 1,25(OH)2D, 25(OH)D, and PTH were measured. 1,25(OH)2D was measured using liquid chromatography tandem mass spectrometry. Bone markers serum N-terminal propeptide of type 1 procollagen (P1NP) and crosslinks (β-cTX) were also measured. Dual-energy x-ray absorptiometry (DXA) of the hip and lumbar spine was performed in 2 centers.</p> <p>Main Outcome Measure(s): QUS of the heel, bone markers P1NP and β-cTX, and DXA of the hip and lumbar spine were measured.</p> <p>Results: A total of 2783 men, mean age 60.0 years (SD 11.0) were included in the analysis. After adjustment for age and center, 1,25(OH)2D was positively associated with 25(OH)D but not with PTH. 25(OH)D was negatively associated with PTH. After adjustment for age, center, height, weight, lifestyle factors, and season, 1,25(OH)2D was associated negatively with QUS and DXA parameters and associated positively with β-cTX. 1,25(OH)2D was not correlated with P1NP. 25(OH)D was positively associated with the QUS and DXA parameters but not related to either bone turnover marker. Subjects with both high 1,25(OH)2D (upper tertile) and low 25(OH)D (lower tertile) had the lowest QUS and DXA parameters and the highest β-cTX levels.</p> <p>Conclusions: Serum 1,25(OH)2D is associated with higher bone turnover and poorer bone health despite being positively related to 25(OH)D. A combination of high 1,25(OH)2D and low 25(OH)D is associated with the poorest bone health.</p&gt

Rescue of Progeria in Trichothiodystrophy by Homozygous Lethal Xpd Alleles

Although compound heterozygosity, or the presence of two different mutant alleles of the same gene, is common in human recessive disease, its potential to impact disease outcome has not been well documented. This is most likely because of the inherent difficulty in distinguishing specific biallelic effects from differences in environment or genetic background. We addressed the potential of different recessive alleles to contribute to the enigmatic pleiotropy associated with XPD recessive disorders in compound heterozygous mouse models. Alterations in this essential helicase, with functions in both DNA repair and basal transcription, result in diverse pathologies ranging from elevated UV sensitivity and cancer predisposition to accelerated segmental progeria. We report a variety of biallelic effects on organismal phenotype attributable to combinations of recessive Xpd alleles, including the following: (i) the ability of homozygous lethal Xpd alleles to ameliorate a variety of disease symptoms when their essential basal transcription function is supplied by a different disease-causing allele, (ii) differential developmental and tissue-specific functions of distinct Xpd allele products, and (iii) interallelic complementation, a phenomenon rarely reported at clinically relevant loci in mammals. Our data suggest a re-evaluation of the contribution of “null” alleles to XPD disorders and highlight the potential of combinations of recessive alleles to affect both normal and pathological phenotypic plasticity in mammals

Traumapotilaan golden hour Kainuun ensihoidossa : Tutkimus traumapotilaan golden hour:n toteutumisesta sekä siihen vaikuttavista tekijöistä Kainuun ensihoidossa

Tutkimuksen tarkoituksena oli kuvailla Kainuun ensihoidon laatua traumapotilaiden hoidossa. Opinnäytetyömme on tehty yhteistyössä Kainuun sosiaali- ja terveydenhuollon kuntayhtymän ensihoidon kanssa. Tutkimuksen tavoitteena oli hyödyntää tutkimusta Kainuun ensihoidossa traumapotilaiden hoidon kehittämisessä. Tutkimuksemme on toteutettu kvantitatiivisena ja retrospektiivisena tutkimuksena. Aineiston keräämiseen käytimme valmista tiedonkeruupohjaa, johon keräsimme 391 ensihoitotehtävän tiedot. Analysoimme tutkimuksen tulokset Excel- ja SPSS-ohjelmilla. Tutkimuksen perusteella 50 % (N= 196) traumapotilaista pääsi kultaisen tunnin aikana lopulliseen hoitopaikkaan. Keskimäärin ensihoitajilla kului kohteessa 21 minuuttia, joka on yli suositellun 10 minuutin. Tutkimuksen mukaan 15 %:lla (N= 58) ensihoitotehtävistä kuljetus päästiin aloittamaan 10 minuutin sisällä. Tutkimuksessa kävi ilmi, että mitä enemmän kohteessa tehtiin hoitotoimenpiteitä, sitä pidempi kohteessa oloaika oli. Tutkimuksessa kävi ilmi, että ensihoitotehtävien kokonaisajasta suurin osa kului matkalla potilaan luokse ja potilaan kuljettamiseen hoitolaitokseen. Tämä selittyy Kainuun alueen pitkillä välimatkoilla. Ensihoitotehtävien kokonaisaika kasvoi huomattavasti, mikäli potilas jatkokuljetettiin Kainuun keskussairaalasta yliopistolliseen sairaalaan Ouluun. Ensihoitotehtävillä, joissa potilas jatkokuljetettiin, aikaa kului merkittävästi keskussairaalassa potilaan tilan stabilointiin ennen jat-kokuljetuksen aloittamista. Tutkimme myös vaikuttaako ensihoitotehtävien kokonaisaikaan eri viranomaisjohtajuudet. Tutkimuksen perusteella voidaan todeta, että poliisijohtoisilla ensihoitotehtävillä kohteessa oloaika oli keskimäärin kaikista lyhyin. Opinnäytetyötämme voidaan hyödyntää ensihoidon laadun kehittämiseksi Kainuun ensihoidossa sekä henkilöstön ammattitaidon ylläpitämiseksi. Tutkimustuloksia voidaan käyttää simulaatiokoulutuksen suunnittelun tukena, jolloin tunnistetaan mahdolliset kehittämishaasteet ensihoitajien toiminnassa. Traumapotilaiden lopullinen hoito tapahtuu aina sairaalassa, jossa on mahdollista saada mm. leikkaushoitoa. Jotta traumapotilas saa parasta mahdollista hoitoa, tulee ensihoidossa pyrkiä mahdollisimman nopeaan kuljetukseen, jolla pyritään turvaamaan traumapotilaan nopea sairaalahoitoon pääsy.Purpose of this study was to describe the quality of emergency care in Kainuu in trauma patients care. Our thesis is made in co-operation with emergency care centre of Kainuu. Objective of the study was to exploit research in developing of care for trauma patients in emergency care of Kainuu. Our study is implemented as a quantitative and retrospective research. For collecting the material, we used ready data collection sheet which we gathered the information of 391 alarms. We analyzed the result of the research by using Excel- and SPSS-programs. Based on the study 50% (N= 196) of trauma patients were transported in the final sequel care facility during the golden hour. Paramedics spent approximately 21 minutes on scene which is over than the recommended 10 minutes. According to the study in 15% (N= 58) of the alarms transportation was achieved to start within 10 minutes. The study showed that the on-scene time was the longer the more procedures were accomplished in the destination. The study also showed that most of the time on the alarms were spent by travelling to the patient and transporting the patient to care facility. This is explained by the long distances of the area of Kainuu. The total time of alarms was highly increased if the patient was sequel transported from central Hospital of Kainuu to University Hospital in Oulu. In alarms which the patient was sequel transported, significant amount of time was spent in central Hospital stabilizing the patient before continuing the transport. We also investigated if authority leaderships affect to the total time spent on alarms. The study lightened out that in those alarms which was lead by police, the on-scene time was averagely shortest. Our thesis can be utilized in developing the quality of emergency care in Kainuu and maintaining the professionality of personnel. Results of the study can be used as a support of simulation education which allows to identify the possible developing challenges in the action of paramedics. The final care of trauma patients always occurs at hospital where multiple procedures are availa-ble. To guarantee that the patient receives best care, must emergency care always strive to quick transportation which secures that patients gets quickly the care they need

Retrospective evaluation of the Dutch pre-newborn screening cohort for propionic acidemia and isolated methylmalonic acidemia:What to aim, expect, and evaluate from newborn screening?

Evidence for effectiveness of newborn screening (NBS) for propionic acidemia (PA) and isolated methylmalonic acidemia (MMA) is scarce. Prior to implementation in the Netherlands, we aim to estimate the expected health gain of NBS for PA and MMA. In this national retrospective cohort study, the clinical course of 76/83 Dutch PA and MMA patients, diagnosed between January 1979 and July 2019, was evaluated. Five clinical outcome parameters were defined: adverse outcome of the first symptomatic phase, frequency of acute metabolic decompensations (AMD), cognitive function, mitochondrial complications, and treatment-related complications. Outcomes of patients identified by family testing were compared with the outcomes of their index siblings. An adverse outcome due to the first symptomatic phase was recorded in 46% of the clinically diagnosed patients. Outcome of the first symptomatic phase was similar in 5/9 sibling pairs and better in 4/9 pairs. Based on the day of diagnosis of the clinically diagnosed patients and sibling pair analysis, a preliminary estimated reduction of adverse outcome due to the first symptomatic phase from 46% to 36%-38% was calculated. Among the sibling pairs, AMD frequency, cognitive function, mitochondrial, and treatment-related complications were comparable. These results suggest that the health gain of NBS for PA and MMA in overall outcome may be limited, as only a modest decrease of adverse outcomes due to the first symptomatic phase is expected. With current clinical practice, no reduced AMD frequency, improved cognitive function, or reduced frequency of mitochondrial or treatment-related complications can be expected