Light and optical techniques have made a profound impact on modern medicine both in diagnostics and in therapy. Therapeutic action of light is based on photomechanical, photothermal, photochemical and photobiological interactions, depending on the wavelength, power density, exposure time and optical properties of tissue and cells. Last decade experienced a growing rise of commercial devices for management of hair growth, where all of them are based on low levels of light resulting into photobiological, non-thermal interaction of photons with cells, a process that recently has received an official term ‘photobiomodulation’. However, the design and analysis of the reported clinical studies are highly debated in a wider scientific community. The picture is further complicated by a virtual lack of proof about the exact molecular targets that mediate the physiological response of skin and hair follicles (HF) to low levels of light. The goal of this project was to investigate the expression of light-sensitive receptors in the human HF and to study the impact of UV-free blue light on hair growth ex vivo. The expression of Cryptochromes 1 and 2 (CRY1, 2), Opsin 2 and 3 (OPN2 and OPN3), but not other Opsins 1, 4 and 5 was detected in the distinct compartments of skin and anagen HF. Evaluation of the physiological role of detected light-sensitive receptors on hair growth was performed by the modulation of photoreceptors activity in HF ex vivo model. HFs treated with KL001, a stabilizer of CRY1 protein that lengthens the circadian period, delayed HF anagen-catagen transition; while silencing of CRY1 induced premature catagen development accompanied by reduced cell proliferation. Silencing of CRY1 in the HF outer root sheath (ORS) cells in vitro caused downregulation of ii genes involved in the control of proliferation; including the cyclin dependent kinase 6 (CDK6). OPN3 also had a positive effect on metabolic activity and proliferation of the ORS cells in vitro. OPN3 silencing resulted in the altered expression of genes involved in the control of proliferation and apoptosis. Investigated CRY1, OPN2 and 3 greatly absorb in the blue to green-region of the visible spectrum. This led us to investigate the effect of blue light on HF growth. Daily treatment with blue light (453 nm, 3.2 J/cm2, 16 nm full width half maximum) prolonged anagen phase in HF ex vivo that was associated with sustained proliferation. In addition, blue light (3.2 J/cm2) significantly stimulated proliferation of ORS cells in vitro. This effect was abrogated by silencing of OPN3. To summarize, CRY 1, OPN 2 and OPN 3 are expressed in the distinct compartments of the HF, including HF stem cells. Blue light (453 nm) at low radiant exposure exerts a positive effect on hair growth ex vivo, potentially via interaction with OPN3. The further research should be conducted to decipher interactions between blue light and the investigated receptors in the HFs. In addition, the beneficial effect of blue light at low radiant exposure on hair growth raises a possibility of increasing therapeutic efficacy when combined with topical chemistry used for management of hair growth.

Lichens are poikilohydric and cannot control water uptake and loss, water relations could therefore impact their distribution. This study examines if morphological, anatomical, and water storage traits could explain distribution of epiphytic species in the lichen genus Usnea. Seven species from oceanic (Norway) and continental areas (Sweden) were studied. Total, internal, and external water holding capacity (WHC, mg H2O cm-2) along with relative water content (WC) were recorded by spraying the thalli with water and measuring mass after shaking and blotting. The specific thallus mass (STM, mg cm-2 - main driver of WHC) was calculated from images of wet thalli. Thickness of anatomical layers (cortex, medulla, and axis) was also measured. Pendent species had lower STM and water storage than shrubby species, most probably an adaptation to water uptake from humid air. Total, internal, and external WHC were higher in the shrubby species than in the pendent ones. The pendent species had the same internal WHC as earlier reports on Bryoria and Alectoria. External water storage decreased for all species as biomass increased. The ratio between total and internal water was twice as high as reported in foliose lichens. Variation in branch diameter was much higher in shrubby than in pendent species. The interspecific differences in water storage reflect regional differences in water sources – oceanic species had higher water storage than pendent continental species, but lower than the shrubby U. hirta. I conclude that both internal and external water storage help to explain distribution of Usnea in Norway and Sweden.

Cortisol is a stress hormone which is released from the adrenals in the Hypothalamic-Pituitary-Adrenal (HPA) axis and plays a major role in animal stress response. Cortisol is used as a stress marker and can be sampled using different methods. A good non-invasive method and a good measure of chronic stress is to measure cortisol through hair. Cortisol is stored in hair for months and therefore reflects chronic stress. The aim of this study was to investigate if cortisol concentration differs depending on coat color. Hair samples from 20 black and white Border collie dogs was analysed and used in this study. Cortisol was extracted with methanol and analysed with ELISA. The results showed no significant difference between black and white coat color within the population while there were individual differences. The results also showed that the sexes do not affect the cortisol concentration. In summary, coat color (black and white) has an effect on cortisol concentration which means that the factor color does need to be taken into account when measuring cortisol through hair.

published_or_final_version / Paediatrics / Doctoral / Doctor of Philosophy

miRNAs are important post-transcriptional regulators of gene expression which play vital roles in the arrays of physiological processes, including skin and hair follicle (HF) development. In this study, the role for miR-214 in the skin and HF development and their postnatal physiological regeneration was investigated. miR-214 exhibits discrete expression patterns in the epidermis and HF in developing and postnatal skin, and is highly expressed in the epithelial stem cells and their lineage-committed progenies. The effects of miR-214 on HF morphogenesis and cycle progression were evaluated by using doxycyclineinducible miR-214 transgenic mice (K14-rtTA/TRE-miR-214). Keratinocyte specific miR-214 overexpression during skin embryogenesis resulted in the partial inhibition of HF induction and formation of the HF reduced in size producing thinner hair. Overexpression of miR-214 in telogen skin caused retardation of the anagen progression and HF growth. Inhibitory effects of miR- 214 on HF development and cycling were associated with supressed activity of stem cells, reduced proliferation in the hair matrix, and altered differentiation. miR-214 induced complex changes in gene expression programs in keratinocytes, including inhibition of cyclins and cyclin-dependent kinases and several essential components of Wnt, Edar, Shh and Bmp signalling pathways, whereas β-catenin acts as a novel conserved miR-214 target. Indeed, the inhibitory effects of miR-214 on HF development were rescued by intracutaneous delivery of pharmacological Wnt activator. Thus, this study demonstrated that by targeting β-catenin and, therefore, interfering with Wnt signalling activity miR-214 may act as one of the upstream effectors of the signalling cascades which govern HF morphogenesis and cycling.

Background Hair cells (HCs) are the sensory receptors in both the auditory and the vestibular organs of the inner ear. Supporting cells (SCs) are non-sensory cells embracing the HCs. Injuries of the HCs by aging, acoustic trauma or ototoxic drugs (mainly aminoglycosides, e.g. gentamicin) and cisplatin, often cause permanent impairment of hearing and balance. Birds and amphibians can regenerate their auditory and vestibular HCs after injury through proliferation of SCs or direct transdifferentiation of a SC into a HC. For mammals this ability is limited and spontaneous HC regeneration occurs only in the vestibular sensory epithelia. The utricle is one of the five vestibular organs and contributes to our balance by registering linear acceleration and head tilts. The aim of this PhD thesis was to investigate morphological and morphometric events during spontaneous HC regeneration following gentamicin exposure in neonatal rat utricular explants. Methods Long-term organ culture of macula utriculi, which is stable and reproducible for up to 28 days in vitro (DIV), was used in all papers in the thesis. HC damage was induced by gentamicin. On 2 DIV the explanted utricular maculae were divided into two groups, a control group and a gentamicin-exposed group. In the latter group macular explants were exposed to gentamicin for 48 hours during 2-3 DIV and then allowed to recover. Morphologic and morphometric evaluations were done from utricles harvested at various time points during 28 DIV. Imaging techniques used were light microscopy, including immunohistochemistry, and transmission electron microscopy. Results In the control group the epithelia were well preserved with a slight decline in HC density after 14 DIV. In the gentamicin-exposed group there was an initial substantial decline in HC density and thereafter the proportion of HCs in relation to SCs increased significantly. Using BrdU as a proliferation marker and myosin 7a as a HC marker, we found no cells that were double marked. At the ultrastructural level, the apical occlusion of the explanted epithelia was intact in both the control and the gentamicin exposed group during the entire in vitro period. Cells that seemed to be in a transitional state, transforming from SCs into HCs were observed in the gentamicin-exposed group. These cells had cytoplasmic extensions basally i.e. foot processes, an assembly of mitochondria basally in the cell or in these foot processes, and often apical SC extensions covering the HC. HCs classified as transitional cells had an increased number of SC connections to their basal parts compared to mature HCs. Conclusions  In these neonatal rat utricular explants: - The morphological structure of the sensory epithelia was well preserved during long-term culture. - The renewal of hair cells after gentamicin exposure occurred through direct transdifferentiation of supporting cells into hair cells. - There was also a proliferative response by the supporting cells, but this supporting cell proliferation did not contribute to the generation of new hair cells. - Cells in a transitional state, showing a characteristic morphology, were observed during the process of transdifferentiation from supporting cells into hair cells. - The tight junctional seal of the epithelia stayed morphologically intact also after gentamicin exposure. - Gap junctions were observed in between supporting cells but not found in between hair cells and supporting cells or between transitional cells and supporting cells.

Hair is power, beauty and seduction: a reflection of ethnicity and religion, and even a canvas for self-expression. A key feature in defining identity and social status, it holds the essence of our individuality. However, once removed from its original and natural setting—the epidermis—hair is seen as waste, and often evokes disgust. The objective of this thesis is to explore human hair, which particularly in the Arabic-Islamic region, carries great significance and raises many religious, cultural, and gender issues. Through design, and informed by critical design theory, I explore how this corporeal material can be reused and re-presented as a means of interrogating the references, symbolism, and connotations of hair both in, and out of, its natural setting.

My work uses hair as both a subject depicted in drawings, paintings, and prints; as well as a medium for sculpture, installation, and video created with synthetic hair pieces and wigs. I am interested in deconstructing gendered codes of appearance, and visions of the ideal woman and man as objects. I remove all identifiable traits from my characters, apart from their hair which appears to be consuming or erasing them. In doing so, I force the people viewing my work to rely on cultural stereotypes associated with hair to identify my characters. My work is heavily influenced by Drag culture and Camp, for their ability to mock identity, gender, and cultural stereotypes and portray them as something fluid that can be constructed and changed on a daily basis, instead of a biological trait forced upon them at birth. I view my artwork as my own form of Drag.

Esta dissertação apresenta a caracterização físico-química e termoanalítica de amostras de cabelo humano. Estudos comparativos entre amostras de queratina comercial e de cabelo caucasiano, oriental, tratados, naturais foram realizados para um melhor entendimento de suas características e comportamento. Para a caracterização das amostras foram utilizadas técnicas como AE, espectroscopia de absorção no infravermelho, difratometria dos raios X, MEV, AFM e análise térmica. Os resultados de análise elementar e espectroscopia no infravermelho não permitem diferenciar as amostras quanto à etnia, sexo, idade ou coloração da fibra. A pulverização das amostras facilita a realização dos ensaios de caracterização, porém amostras na forma de fio são mais adequadas para os estudos de DSC. As imagens de MEV e AFM evidenciaram grandes variações na estrutura superficial de amostras de cabelo natural e submetidas a tratamentos de beleza. Os resultados de análise térmica forneceram informações quanto ao comportamento térmico do cabelo, em relação à desidratação, região da transição vítrea e as etapas de decomposição térmica das amostras na forma fio e pó. O cabelo possui elevada concentração de queratina, como descrito na literatura, independente da matriz, e quando submetido a processos de modelagem, que envolvam elevada temperatura (secadores, piastra/prancha e baby liss) pode sofrer danos irreversíveis à estrutura da fibra capilar. / This dissertation presents the physico-chemical and thermoanalytical characterization of human hair samples. Comparative studies of samples of commercial keratin and caucasian, oriental, treated, natural hair were conducted to better understand their characteristics and behavior. For the sample characterization were used elemental analysis, infrared spectroscopy, X-ray diffraction, SEM, AFM and thermal analysis techniques. The results of elemental analysis and infrared spectroscopy did not vary between samples with respect to ethnicity, age, color fiber and belonged to individuals male or female. Samples in powder form facilitate the testing of characterization, but in the form of wire samples are more suitable for DSC studies. The SEM and AFM images showed large variations in the surface structure of samples subjected to natural hair and beauty treatments. The thermal analysis results provide information about the thermal behavior of hair, compared to dehydration, glass transition region and thermal decomposition steps of samples in wire and powder form. The hair has a high concentration of keratin, as described in the literature, regardless of the array. And, when subjected to modeling processes involving high temperature and (dryers, piastre / board and baby liss) can cause irreversible damage to the structure of the hair fiber.

Clinical and forensic toxicology analysts rely heavily in their daily tests on the analysis of the conventional samples (blood and urine). However, these specimens are limited in the time scale they reflect with regard to drug intake history and also in terms of drug stability within the matrices. Alternative matrices such as hair, oral fluids and dried blood spots (DBS) provide new horizons and new opportunities. Drugs incorporated within hair are very stable. Hair also provides a very long detection window, for at least one year, if not a lot longer. Oral fluids on the other hand are non-intrusive, easy to collect and much cleaner sample matrix than blood or urine. DBS also offer great drug stability, are easy to collect, faster to analyse and suitable for automated analysis. However, a number of studies are needed to assess the limits of these alternative samples in terms of the correlation of their results with the results of conventional samples and with regard to drug stability. Such studies will enable a more reliable and confident interpretation of results obtained from these matrices especially for medico-legal purposes. The main aims of this research were: to develop and validate analytical methods for detection and quantitation of drugs of use and abuse in hair, oral fluids, blood and DBS samples, to investigate the correlation between dose and drug concentration in hair, blood and oral fluids after controlled chronic drug administration, to investigate the stability of anti-psychotic drugs in DBS (from patients) stored under different conditions and the effect of addition of preservative, and to investigate the alcohol intake prevalence among Kuwaiti drug addicts and correlate these results with selfreported intake. As the majority of drugs were basic, an extraction method based on methanolic incubation was developed for detection of basic/weak basic drugs in hair. It was compared to alkaline digestion (with NaOH) followed by liquid-liquid extraction (LLE). Detection was achieved by LC-MS/MS (Sciex2000) after separation on a C18 column. When applying both methods on positive authentic hair samples the results showed that the methanolic method was capable of extracting most basic drugs in hair but only partially, while the alkaline digestion method was found to degrade V some unstable drugs like sulpiride, but was capable of fully extracting the alkaline stable drugs such as quetiapine. After development and validation of the LLE-LC-MS(Exactive) method for the analysis of anti-psychotics in blood, oral fluids and hair, an investigation was carried out on the correlation pattern between trough concentrations in those three matrices. The most significant correlation coefficients (r) found were those between blood and hair concentrations, procyclidine r=0.83 (18 subjects p=<0.001), risperidone r=0.96 (14 subjects p=<0.001), haloperidol r=0.90 (10 subjects p=<0.001), OH-risperidone r=0.24 (13 subjects p=>0.44), quetiapine r=0.28 (14 subjects p=>0.33) and chlorprothixene r=0.32 (13 subjects p=>0.32). Among the interesting results was the strong correlation found between drugs half-lives and the mean ratio of hair concentration/dose (r=0.96, p=<0.003). The stability of anti-pyschotics in DBS from patients’ samples was assessed by storing them at four different temperatures (25, 4, -20 and -80°C) with and without prior impregnation of the DBS cards with sodium fluoride. After development and validation of the LLE-LC-MS method, samples were analysed at days 0, 45, 90 and 180. Results showed good stability of all the compounds (procyclidine, quetiapine, risperidone, OH-risperidone, chlorprothixene and haloperidol) in all the different storage conditions and no significant increase or decrease in drug concentrations with sodium fluoride impregnation. Finally, after trials with five different HPLC columns, two SPE cartridges, two LLE extraction procedures and two mass spectrometer instruments, a method was developed and validated for the detection and quantitation of alcohol’s minor and specific metabolite in hair, ethyl glucuronide (EtG). The method has a limit of detection (LOD) of 3pg/mg and lower limit of quantitation (LLOQ) of 9pg/mg. This method was applied to 59 hair samples from patients at a general addiction centre and alcohol prevalence was investigated and its correlation with self-reported use was investigated.