Title: The biomechanical effects of levator ani muscle laceration injuries after vaginal delivery Objectives: The aim of this thesis is to sum up current knowledge about the normal structure and function of levator ani muscle and findings about dysfunctions of a pelvic floor. By means of biomechanical instruments to analyse how the lower part of levator ani muscle closes (puborectalis muscle) during unilateral avulsion lesion. On the basis of computer simulation of biomechanical properties of the pelvic floor during avulsion lesion to describe the theoretical solutions for the therapy of the main types of dysfunctions of the pelvic floor. Methods: Biomechanical analysis was used with a help of computer model of muscular pelvic floor with a help of the ABAQUS model. This model with matched properties of muscular tissue was influenced by the standard pressure which influences the pelvic floor for a person of 80 kilos standing at rest. This model simulated unilateral avulsion lesion and biomechanical variables were observed during compensatory activation of uninjured parts of levator with the activity 100%, 50% and 10%. The map of the muscular tone and the rate of movement of the muscles of the pelvic floor were evaluated. Results: Only minimal movement is observed in the intact pelvic floor during...

The work provides a comprehensive overview of the issues hallux rigidus with a focus on the first metatarsophalangeal joint replacement and development of our own implant. The development was built to perform anatomical studies, the results were the basis for the construction of hemiarthroplasty and total arthroplasty. It was necessary to measure the marrow cavities of the distal part of first metatarsal and proximal half of proximal phalanx. We measured the size of the metatarsal head in two planes, and its tendency to diaphysis on the dry preparations. Through these studies we obtained valid data for the construction all components of both hemiarthroplasty and total arthroplasty of specifying the size spectrum. We have verified and then corrected the shape of implant treatment during post-mortem tests on the models. The result is a new type of arthroplasty with their own design to guarantee restoration of joint function and coated with a high osteointegral potential. In clinical studies, we performed 22 implantations of hemiarthroplasty and one implantation of total arthroplasty. Clinical results suggest the fact that the implant will be successful. However the ultimate answer to this question will provide long-term study. The other results presented with a detailed anatomical description show to...

The work provides a comprehensive overview of the issues hallux rigidus with a focus on the first metatarsophalangeal joint replacement and development of our own implant. The development was built to perform anatomical studies, the results were the basis for the construction of hemiarthroplasty and total arthroplasty. It was necessary to measure the marrow cavities of the distal part of first metatarsal and proximal half of proximal phalanx. We measured the size of the metatarsal head in two planes, and its tendency to diaphysis on the dry preparations. Through these studies we obtained valid data for the construction all components of both hemiarthroplasty and total arthroplasty of specifying the size spectrum. We have verified and then corrected the shape of implant treatment during post-mortem tests on the models. The result is a new type of arthroplasty with their own design to guarantee restoration of joint function and coated with a high osteointegral potential. In clinical studies, we performed 22 implantations of hemiarthroplasty and one implantation of total arthroplasty. Clinical results suggest the fact that the implant will be successful. However the ultimate answer to this question will provide long-term study. The other results presented with a detailed anatomical description show to...

Einleitung: Es gibt vier Arten von Neuweltkamelen: Die domestizierten Alpakas (Vicugna pacos) und Lamas (Lama glama) sowie ihre wilden Vorfahren Vikunja (Vicugna vicugna) und Guanako (Lama guanicoe). Neuweltkamele werden in Europa als Nutz- und Liebhabertiere gehalten und sind schon seit Jahren Teil des Patientengutes der deutschen Tierärzte. Eine häufige Erkrankung des Bewegungsapparates dieser Exoten ist die metakarpo/-tarsophalangeale Hyperextension, auch „Fesselträgerniederbruch“ genannt. Es bestehen noch immer große Wissenslücken, was die physiologische Anatomie der kameliden Fesselgelenksregion betrifft. So finden sich in der Literatur widersprüchliche Aussagen zu den Sehnen und Strukturen der Articulatio metacarpo/- tarso-phalangealis bei verschiedenen Arten. Diese gilt es abzuklären, um ein grundsätzliches Verständnis für die Morphologie der entscheidenden Strukturen des Fesseltrageapparates zu erlangen sowie Grundlagen für die klinische Diagnostik zu schaffen. Ziele der Untersuchungen: Die vorliegende Forschungsarbeit klärt folgende Fragen zu den Strukturen, die dem Fesselgelenk der Neuweltkamele palmar bzw. plantar assoziiert sind: Bestehen makroskopisch- anatomische Unterschiede zwischen den Arten? Welche physiologischen Querschnittsflächen besitzen der Musculus interosseus der 3. und 4. Zehe (im folgenden Musculus interosseus genannt), die oberflächliche und die tiefe Beugesehne bei den einzelnen Arten der Neuweltkamele? Zeigen sie artspezifisch unterschiedliche Ausprägungen? Wie setzt sich der Musculus interosseus bei diesen Tierarten histologisch zusammen? Gibt es einen Zusammenhang zwischen dem Muskelfaseranteil des Musculus interosseus und der betrachteten Spezies? Tiere, Material und Methoden: Die Gliedmaßen von je 14 Tieren pro Art wurden distal des Karpus respektive Tarsus abgesetzt. Insgesamt 64 Gliedmaßen wurden mit Standardinstrumentarium seziert, um die makroskopische Anatomie darzulegen. Je eine Vorder- und eine Hintergliedmaße von 40 Tieren wurden für eine morphometrische Untersuchung, der Rest für eine histologische Untersuchung beprobt. Im Rahmen der morphometrischen Messungen wurde die Querschnittsfläche der oberflächlichen und tiefen Beugesehne sowie des Musculus interosseus an verschiedenen Probennahmepunkten dokumentiert. Von den Musculi interossei der restlichen Gliedmaßen wurden Gewebsschnitte angefertigt, mit einer Trichromfärbung gefärbt und mittels eines Scanners digitalisiert. Daraufhin wurden die Gewebsanteile qualitativ sowie der Muskelfaseranteil des Musculus interosseus quantitativ untersucht und ausgewertet. Die Messungen der Morphometrie und Histologie erfolgten digital mithilfe eines kostenlosen Bildauswertungsprogammes. Ergebnisse: Es konnten makroskopisch keine morphologischen Unterschiede zwischen den untersuchten Arten in Vorkommen oder Ausprägung der Strukturen des Fesseltrageapparates festgestellt werden. In einer Abgrenzung zu Quellen aus der Literatur halten wir fest, dass weder Unterstützungssehnen des Musculus interosseus zur Strecksehne noch Interdigitalbänder gefunden werden konnten. Musculi lumbricales traten meist einzeln, nicht paarweise, auf. Die Ergebnisse der morphometrischen Untersuchung zeigten große individuelle Schwankungen der Sehnenquerschnittsfläche, welche nur unvollständig durch die erhobenen Einflussfaktoren zu erklären sind. Indikatoren für die Größe des Tieres waren die besten Prädiktoren für die Querschnittsfläche je Probennahmepunkt. Unterschiede zwischen Vorder- und Hinterbeinen sowie die Artzugehörigkeit spielten hingegen eine untergeordnete Rolle. Die histologische Analyse des Musculus interosseus zeigte eine komplexe Struktur mit unterschiedlichen Gewebskomponenten wie straffem Bindegewebe, lockerem Bindegewebe, Fett- und Muskelgewebe sowie Nerven und Gefäßen. Einlagerungen von Adipozyten sind vor allem am proximalen und distalen Probennahmepunkt zu finden, der Anteil an quergestreiften Muskelfasern war auf mittlerer Ebene am höchsten. Muskelfasern waren bis in die Endsehnen des Musculus interosseus nachweisbar. Der Prozentsatz an Muskelgewebe für die gesamte Struktur belief sich auf 1,7 ± 2,8 %. Alpakas zeigten einen signifikant höheren Anteil an Muskelfasern als die anderen Arten. Schlussfolgerungen: Die unterstützenden Strukturen am Fesselgelenk der Neuweltkamele sind komplex und einzigartig. Makroskopisch und strukturell können die vier Arten von Neuweltkamelen gleichgesetzt werden, da sich zwar die Größe der Strukturen, nicht aber ihre Proportionen zueinander ändern. Die starken individuellen Schwankungen der Querschnittsflächen von oberflächlicher Beugesehne, tiefer Beugesehne und Musculus interosseus verschlechtern die Aussicht, diesen Wert als Orientierungshilfe in der klinischen Diagnostik einsetzen zu können. Die histologische Zusammensetzung des Musculus interosseus zeigt artspezifisch Unterschiede im Anteil von Muskelfasern, deren Ursache in der physischen Aktivität der Individuen oder in genetischen Unterschieden durch die Domestikation begründet liegen könnte.:Inhalt 1 Einleitung 1 2 Literaturübersicht 3 2.1 Evolution, Geschichte und Zoologie der Neuweltkamele 3 2.1.1 Biomechanik und Evolution 4 2.2 Funktionelle Anatomie der distalen Gliedmaße der Neuweltkamele 5 2.2.1 Integument 6 2.2.2 Knöcherne Strukturen 6 2.2.3 Sehnen und Bänder 6 2.2.4 Neurovaskuläre Strukturen 10 2.2.5 Gliedmaßenstellung und Biomechanik der distalen Gliedmaße 11 2.3 Allgemeines zu Aufbau und Funktion von Sehnen und Bändern 12 2.3.1 Makroskopisch-anatomische Definition und Funktion 12 2.3.2 Aufbau von Sehnen und Bändern 13 2.3.3 Unterschiede zwischen Sehnen und Bändern 13 2.3.4 Ursprung und Ansatz 14 2.3.5 Nerven- und Gefäßversorgung 14 2.3.6 Einflussfaktoren auf Sehnen- und Bandstruktur 14 2.4 Allgemeines zu Aufbau und Funktion des Musculus interosseus 15 2.4.1 Morphologie der Mm. interossei ausgewählter domestizierter Arten 15 2.4.2 Gewebsstruktur der Mm. interossei ausgewählter domestizierter Arten 15 2.4.3 Begrifflichkeiten und Synonyme 16 2.5 Pathologien an Sehnen und Bändern der distalen Gliedmaße der Neuweltkamele 17 2.6 Morphometrie des Musculus interosseus und der Beugesehnen 18 2.6.1 Die Querschnittsfläche von Sehnen und Bändern 18 2.6.2 Klinische Bedeutung der Querschnittsfläche 19 2.6.3 Methoden zur Bestimmung der Querschnittsfläche von Sehnen und Bändern 19 2.6.4 Messung der Sehnenquerschnittsfläche per Ultraschalluntersuchung 20 2.7 Histologische Methoden zur Untersuchung des Musculus interosseus 20 2.7.1 Probenaufbereitung 20 2.7.2 Färbemethoden 21 2.7.3 Bestimmung von Gewebsanteilen in der Histologie 22 2.7.4 Feingewebliche Struktur des M. interosseus des Pferdes 22 2.7.5 Feingewebliche Struktur des M. interosseus bei Neuweltkamelen 23 2.7.6 Klinische Bedeutung 24 3 Wissenschaftliche Originalarbeiten 25 3.1. Comparative anatomic and morphometric examination of the interosseous muscle, sesamoid ligaments and flexor tendons of the fetlock in South American Camelids 25 3.1.1 Darstellung der Eigenleistung 38 3.2. Suspensory ligament or interosseous muscle? Histology of the interosseous muscle of South American Camelids 39 3.2.1 Darstellung der Eigenleistung 50 4. Diskussion 51 4.1 Methodik 51 4.1.1 Südamerika als Studienort 51 4.1.2 Stichprobenauswahl: Tiere 53 4.1.3 Auswahl der Messpunkte 54 4.1.4 Herangehensweise an die morphometrische Messung 56 4.1.5 Messgenauigkeit Morphometrie 57 4.1.6 Prozessierung histologischer Proben 59 4.2 Anatomie: Abgleich mit Ergebnissen anderer Studien an Neuweltkamelen sowie Vergleich mit Pferd und Rind 60 4.2.1 Exkurs: Die Rolle der Subjektivität in der anatomischen Beschreibung 60 4.2.2 Verbindung der Fascia palmaris manus mit der oberflächlichen Beugesehne und dem M. interosseus 61 4.2.3 Ringbänder 63 4.2.4 Oberflächliche Beugesehne 64 4.2.5 Tiefe Beugesehne und Musculus lumbricalis 64 4.2.6 Musculus interosseus 65 4.2.7 Sesambeinbänder 66 4.2.8 Bursa podotrochlearis 67 4.2.9 Distales Sesambein 67 4.2.10 Interdigitalbänder 67 4.2.11 Einfluss der Gliedmaßenachse auf die anatomischen Strukturen 68 4.3 Weitere Ergebnisse 69 4.3.1 Korrelation der Beugesehnen mit dem Musculus interosseus 69 4.4 Kernergebnisse im Hinblick auf die vergleichende Anatomie von Lama, Alpaka, Guanako und Vikunja 70 4.5 Schlussfolgerungen in Bezug auf Zoologie, Domestikation und Biomechanik 71 4.6 Klinische Relevanz der Ergebnisse 72 4.7 Ausblick 73 5 Zusammenfassung 74 6 Summary 76 7 Literaturverzeichnis 78 8 Anhang 88 / Introduction: There are four species of South American Camelids: The domesticated alpaca (Vicugna pacos) and lama (Lama glama) as well as their wild ancestors vicuna (Vicugna vicugna) and guanaco (Lama guanicoe). South American Camelids in Europe are being kept for production and as companion animals. They are frequently being presented in veterinary practice. A typical pathology of the locomotive apparatus of these animals is the condition of metacarpo/-tarsophalangeal hyperextension, commonly described as the animal being “down in the fetlock”. We know little, however, about the physiological anatomy of the lamoid fetlock region. There are discrepancies in literature in the description of the anatomical structures of the metacarpo/-tarsophalangosesamoid joint between different South American Camelid species. These are to be clarified in order to gain a thorough understanding of the morphology of important structures of the suspensory apparatus of the fetlock and as a foundation for clinical diagnostics. Objectives of the investigations: This research answers the following basic questions about the structures which are palmarly/plantarly associated with the lamoid fetlock: Are there differences in macroscopic anatomy between species? What cross-sectional areas do the physiological Musculus interosseus of digit III and IV (from hereon called “interosseous muscle”), the superficial and the deep digital flexor tendon possess? Are there differences in relation to species? How is the interosseous muscle histologically composed in these animals? Do the tissue components vary depending on the species? Materials and methods: The distal extremity of 14 animals per species was harvested distally to the carpus and tarsus. 64 limbs in total were dissected with standard tools for macroscopic anatomy. One fore- and one hindlimb of 40 animals were sampled for morphometric measurements, the rest for histology. The cross-sectional area of the superficial and deep digital flexor tendon as well as the interosseous muscle were determined at different sampling levels along the extremity. Histological slides stained with a trichromic dye were obtained from the interosseous muscle to be digitalized with a histological scanner. Different tissue components were analysed qualitatively, the amount of muscle tissue within the interosseous muscle quantitatively. A freeware for scientific image analysis was employed for both the morphometric as well as the histologic measurements. Results: No morphological differences regarding the macroscopic structures of the suspensory apparatus of the fetlock could be detected in the comparative anatomic examination of the four species of South American Camelids. We neither found extensor branches of the interosseous muscle nor interdigital ligaments, contradicting some sources. Lumbricalis muscles mostly appeared as single muscles, not as pairs. The results of the morphometric investigations showed large individual variation of tendon cross-sectional area at each sample point, which couldn’t be completely explained by the statistically monitored influencing factors. The best predictor for the cross-sectional area of each tendon were indicators of the animal´s size, while differences between fore- and hindlimb as well as the individual’s species were of only minor influence. Histologic analyses of the lamoid interosseous muscle showed a complex structure with different tissue components such as dense and loose connective tissue, adipose tissue and muscle fibers as well as nervous tissue and vessels. Infiltration by adipocytes could be seen mostly at the proximal and distal sample levels. The amount of muscle tissue was greatest at mid-level. Muscle fibers could be found up until the terminating branches. Striated muscle fibers made up 1.7 ± 2.8 % of the total cross-sectional area of the interosseous muscle. Alpacas showed a significantly larger percentage of muscle fibers than all other species. Conclusions: The sustaining structures of the lamoid fetlock are complex and unique to the investigated species. Macroscopically and in structure alpaca, lama, guanaco and vicuna can be treated as equals as only size, but not proportions of the examined structures vary. The large individual variation of the cross-sectional area of the superficial digital flexor tendon, deep digital flexor tendon and the interosseous muscle lower the chances of using this measure in clinical diagnostics in the future. Significant histologic differences in the amount of muscle fibers within the lamoid interosseous muscle exist, and these are related to the factor species. The reason for these variations might be due to individual physical activity and training or might as well be found in genetics and be related to the domestication process.:Inhalt 1 Einleitung 1 2 Literaturübersicht 3 2.1 Evolution, Geschichte und Zoologie der Neuweltkamele 3 2.1.1 Biomechanik und Evolution 4 2.2 Funktionelle Anatomie der distalen Gliedmaße der Neuweltkamele 5 2.2.1 Integument 6 2.2.2 Knöcherne Strukturen 6 2.2.3 Sehnen und Bänder 6 2.2.4 Neurovaskuläre Strukturen 10 2.2.5 Gliedmaßenstellung und Biomechanik der distalen Gliedmaße 11 2.3 Allgemeines zu Aufbau und Funktion von Sehnen und Bändern 12 2.3.1 Makroskopisch-anatomische Definition und Funktion 12 2.3.2 Aufbau von Sehnen und Bändern 13 2.3.3 Unterschiede zwischen Sehnen und Bändern 13 2.3.4 Ursprung und Ansatz 14 2.3.5 Nerven- und Gefäßversorgung 14 2.3.6 Einflussfaktoren auf Sehnen- und Bandstruktur 14 2.4 Allgemeines zu Aufbau und Funktion des Musculus interosseus 15 2.4.1 Morphologie der Mm. interossei ausgewählter domestizierter Arten 15 2.4.2 Gewebsstruktur der Mm. interossei ausgewählter domestizierter Arten 15 2.4.3 Begrifflichkeiten und Synonyme 16 2.5 Pathologien an Sehnen und Bändern der distalen Gliedmaße der Neuweltkamele 17 2.6 Morphometrie des Musculus interosseus und der Beugesehnen 18 2.6.1 Die Querschnittsfläche von Sehnen und Bändern 18 2.6.2 Klinische Bedeutung der Querschnittsfläche 19 2.6.3 Methoden zur Bestimmung der Querschnittsfläche von Sehnen und Bändern 19 2.6.4 Messung der Sehnenquerschnittsfläche per Ultraschalluntersuchung 20 2.7 Histologische Methoden zur Untersuchung des Musculus interosseus 20 2.7.1 Probenaufbereitung 20 2.7.2 Färbemethoden 21 2.7.3 Bestimmung von Gewebsanteilen in der Histologie 22 2.7.4 Feingewebliche Struktur des M. interosseus des Pferdes 22 2.7.5 Feingewebliche Struktur des M. interosseus bei Neuweltkamelen 23 2.7.6 Klinische Bedeutung 24 3 Wissenschaftliche Originalarbeiten 25 3.1. Comparative anatomic and morphometric examination of the interosseous muscle, sesamoid ligaments and flexor tendons of the fetlock in South American Camelids 25 3.1.1 Darstellung der Eigenleistung 38 3.2. Suspensory ligament or interosseous muscle? Histology of the interosseous muscle of South American Camelids 39 3.2.1 Darstellung der Eigenleistung 50 4. Diskussion 51 4.1 Methodik 51 4.1.1 Südamerika als Studienort 51 4.1.2 Stichprobenauswahl: Tiere 53 4.1.3 Auswahl der Messpunkte 54 4.1.4 Herangehensweise an die morphometrische Messung 56 4.1.5 Messgenauigkeit Morphometrie 57 4.1.6 Prozessierung histologischer Proben 59 4.2 Anatomie: Abgleich mit Ergebnissen anderer Studien an Neuweltkamelen sowie Vergleich mit Pferd und Rind 60 4.2.1 Exkurs: Die Rolle der Subjektivität in der anatomischen Beschreibung 60 4.2.2 Verbindung der Fascia palmaris manus mit der oberflächlichen Beugesehne und dem M. interosseus 61 4.2.3 Ringbänder 63 4.2.4 Oberflächliche Beugesehne 64 4.2.5 Tiefe Beugesehne und Musculus lumbricalis 64 4.2.6 Musculus interosseus 65 4.2.7 Sesambeinbänder 66 4.2.8 Bursa podotrochlearis 67 4.2.9 Distales Sesambein 67 4.2.10 Interdigitalbänder 67 4.2.11 Einfluss der Gliedmaßenachse auf die anatomischen Strukturen 68 4.3 Weitere Ergebnisse 69 4.3.1 Korrelation der Beugesehnen mit dem Musculus interosseus 69 4.4 Kernergebnisse im Hinblick auf die vergleichende Anatomie von Lama, Alpaka, Guanako und Vikunja 70 4.5 Schlussfolgerungen in Bezug auf Zoologie, Domestikation und Biomechanik 71 4.6 Klinische Relevanz der Ergebnisse 72 4.7 Ausblick 73 5 Zusammenfassung 74 6 Summary 76 7 Literaturverzeichnis 78 8 Anhang 88

Sertoli cells (SCs) are somatic cells of testicular tissue that are involved in spermatogenesis and maturation of germ cells. They are currently being extensively studied for their immunomodulatory abilities, and recent studies have shown that they share some properties with mesenchymal stromal cells (MSCs). Detailed characterization of SCs and clarification of their role in testicular tissue is crucial for potential use of SCs as a therapeutic tool in regenerative medicine. Cell culture of Xenopus tropicalis immature Sertoli cells (XtiSCs) and Mus musculus (mSCs) Sertoli cells were established in the Laboratories of Developmental Biology and Immunoregulations, Faculty of Science, Charles University. Previous research has characterized XtiSCs and demonstrated their multipotent potential by in vitro differentiation into a mesodermal line. Following this research, one of the goals of the diploma project was the induction of in vitro differentiation of XtiSC into other cell types, which would verify the differentiation potential of XtiSCs. The mSC expression profile confirmed the somatic origin of this culture as well as the transcription of Sertoli cell gene markers. Differentiation of mSCs along the mesodermal line into osteoblasts, chondrocytes and adipocytes has been successfully induced in vitro....

<p> The age at which a juvenile female reaches sexual maturity can be modulated by a variety of environmental and social factors. Experiments described in this thesis were designed to enhance the current understanding of the relationships among three variables that influence the onset of sexual maturation in female mice (Mus musculus), including: [1] exposure to dietary phytoestrogens during development, [2] variations in prenatal androgens, and [3] the presence or absence of genetically-unrelated males after weaning. For the first time, age at onset of male-induced female puberty was investigated using non-invasive behavioural and fertility measures. Through enzyme immunoassay procedures, daily output of urinary creatinine, 17P-estradiol, and progesterone was profiled in developing females that were either isolated or exposed to adult males. Uterine and ovarian tissue was also measured in such females, and male exposure was observed to increase reproductive tissue mass and was influenced by prior androgen exposure in interaction with diet and male presence. Male-exposed females fed a diet containing phytoestrogens immediately became sexually receptive when housed directly with males, and they conceived earlier than females in other conditions. Females with longer anogenital distance, which reflects higher in utero androgen exposure, displayed more escape attempts and aggressive posturing in the direct presence of males, especially when they had been housed near males and fed the phytoestrogen-containing diet. Urinary 17P-estradiol was substantially reduced in females raised on the phytoestrogenfree diet. Urinary output of progesterone was not strongly influenced by diet. Maleexposed females ' output of progesterone and 17P-estradiol was more dynamic in comparison to that of isolated females. The size of this effect depended on diet, prior androgen exposure, and whether urinary steroid measures were adjusted by urinary creatinine. Urinary creatinine was elevated by the low phytoestrogen diet and reduced by male exposure. These data suggest that dietary phytoestrogens and in utero androgen exposure interact with presence or absence of males in determining the age at onset of sexual maturity in developing females. </p> <p> A final experiment was designed to examine two components of adult male urine, preputial gland emissions and unconjugated estrogens, that have been posited to act on females to advance reproductive maturation. Intact and preputialectomized males were compared in their output of urinary creatinine, 17~-estradiol, and testosterone, and in their influence on reproductive tissue in juvenile females. Lack of preputial glands did not hinder the capacity of males to induce uterine and ovarian growth in females. Male urinary creatinine was reduced by exposure to juvenile females. Creatinine-adjusted 17~estradiol and testosterone were greater in female-exposed males, regardless of whether the preputial glands were present. Based on these findings and those reported elsewhere, it is probable that male excreted urinary steroids are important in regulating reproductive changes in developing females exposed to males. </p> / Thesis / Doctor of Philosophy (PhD)

No description available.

The skin has a system that can detect light in a fashion similar to the retina. Although its presence was initially reported almost 20 years ago, only in 2011 functional studies started to be reported. The biological clock of the skin has also been reported in the beginning of the century, but its function and relevance still remain unexplored. Thus, this Ph.D. project was designed to explore the functionality of both systems in melanocytes, and whether the disruption of these systems is associated with the development of melanoma cancer. Using in vitro, in vivo, and bioinformatics approaches, we have shown that: 1) the biological clock of malignant melanocytes is more responsive to visible light, UVA radiation, estradiol, and temperature compared to normal cells; 2) UVA radiation is detected by melanopsin (OPN4) and rhodopsin (OPN2), which triggers a cGMP related cascade that leads to immediate pigment darkening (IPD) in normal and malignant melanocytes; 3) in addition to detecting UVA radiation, OPN4 also senses thermal energy, which activates the biological clock of both normal and malignant melanocytes; 4) regarding the biological clock, we have provided several layers of evidence that proves that in melanoma a chronodisruption scenario is established compared to healthy skin and/or normal pigment cells; 5) in vivo tumor samples display a low amplitude circadian rhythm of clock gene expression and an ultradian oscillatory profile in melanin content; 6) a non-metastatic melanoma leads to a systemic chronodisruption, which we suggest that could favor the metastatic process; 7) in human melanoma, we demonstrated the role of BMAL1 as a prognostic marker and a putative marker of immune therapy success. Taken altogether, these results significantly contributed to the literature as it brought to light new and interesting targets and processes, which will be explored in future projects / A pele possui um sistema que pode detectar luz de forma análoga à retina. Embora a presença deste sistema tenha sido inicialmente descrita quase há 20 anos, apenas no ano de 2011 estudos funcionais começaram a ser relatados. Sabe-se que o relógio biológico da pele também foi identificado no início do século, mas sua função e relevância ainda continuam pouco exploradas. Diante deste cenário, este projeto de doutorado foi desenhado para investigar a funcionalidade de ambos os sistemas em melanócitos e se perturbação dos mesmos estaria associada com o desenvolvimento de melanoma. Através do uso de abordagens in vitro, in vivo e de bioinformática, nós demonstramos que: 1) o relógio biológico de melanócitos malignos é mais responsivo à luz visível, radiação UVA, estradiol e temperatura comparado ao de células normais; 2) a radiação UVA é detectada por melanopsina (OPN4) e rodopsina (OPN2), que ativam uma via de sinalização dependente de GMPc, levando ao processo de pigmentação imediata (IPD) em melanócitos normais e malignos; 3) além de detecção de radiação UVA, a OPN4 também detecta energia térmica que, por sua vez, ativa o relógio biológico de melanócitos normais e malignos; 4) relativo ao relógio biológico, provamos por diferentes abordagens que, no melanoma, um cenário de cronoruputura está estabelecido em comparação a pele saudável e/ou melanócitos; 5) tumores in vivo apresentam um ritmo circadiano de baixa amplitude na expressão dos genes de relógio e um ritmo ultradiano oscilatório no conteúdo de melanina; 6) um melanoma não metastático leva a um quadro sistêmico de cronoruptura, o qual sugerimos favorecer o processo de metástase; 7) em melanoma humano, demonstramos o papel do gene BMAL11 como marcador de prognóstico e um possível indicador de sucesso de imunoterapias. Portanto, este projeto contribuiu de forma significante para a literatura científica uma vez que trouxe à luz novos e interessantes alvos terapêuticos e processos, os quais serão explorados em projetos futuros

Despite extensive international acceptance of the critical role of mammalian post-dispersal seed predation in many plant communities, in New Zealand we have limited knowledge of these predators’ influence on plant recruitment in our forests. The principle objective of my thesis was to determine the importance of exotic mammals as post-dispersal seed predators in a New Zealand conifer-broadleaf forest remnant. To address this goal, I used a series of field-based experiments where the actions of different post-dispersal seed predators were separated by wire-mesh exclosures. My study was conducted at Mount Peel Forest Park Scenic Reserve, South Canterbury, New Zealand. Being a human modified conifer forest currently dominated by broadleaf species, it is typical of forest remnants in New Zealand. This presented an opportunity to study a wide range of both potential post-dispersal seed predators and broadleaf tree species. My findings indicate that exotic mammals are not only post-dispersal seed predators at Peel Forest, but are responsible for the majority of post-dispersal predation events observed. Ship rats (Rattus rattus) were the dominant post-dispersal seed predators, while brushtail possums (Trichosurus vulpecula), house mice (Mus musculus) and native invertebrates were also important post-dispersal seed predators for several tree species. Through use of time-lapse video and cafeteria experiments I found that exotic mammalian seed predators, when compared to native invertebrate seed predators, preyed upon larger-seeded plant species and were responsible for considerable seed losses of several tree species. However, exotic mammalian seed predators do share several foraging characteristics with native invertebrate seed predators, as predators foraged in similar habitats and responded in a similar way to changes in seed density. In investigating if post-dispersal seed predation by mammals had a flow-on effect to plant recruitment, I observed natural seedling densities at Peel Forest were significantly higher in the absence of mammalian seed predators, but I found no evidence that the presence of mammals significantly altered the overall species richness. At the community level, I did not find an interaction between habitat and exotic mammals, however I present evidence that for individual plant species a significant mammal : habitat interaction occurred. Consequently, even though my cafeteria experiment implied there was no significant difference in the overall amount of seed preyed upon within different habitats, the less favourable microsite conditions for germination under an intact continuous canopy allows mammals to exacerbate habitat-related patterns of seed mortality and have a noticeable effect on seedling establishment. In an effort to validate the use of manipulative experiments to predict the long-term effect of post-dispersal seed predation on plant dynamics, I attempted to link results of my cafeteria experiment with observed seedling abundance at Peel Forest. Seven tree species were used in this comparison and a strong correlation was observed. This result shows that the level of post-dispersal seed predation determined in the cafeteria experiment provided a good predictor of the effect of mammalian post-dispersal seed predation on seedling establishment. To fully gauge the impact of mammalian post-dispersal seed predators on seedling establishment, the relationship between these seed predators and the type of recruitment limitation experienced by a plant species was also investigated. By using a combination of seed addition, plot manipulations and seed predator exclusion I was able to investigate this relationship. I found evidence that seed limitation at Peel Forest is positively correlated with seed size, and that while mammalian post-dispersal seed predators can further reduce plant recruitment of plant species experiencing seed limitation, the influence of mammals in determining plant recruitment was limited for plant species experiencing microsite limitation. My study has proven that exotic mammals are now the dominant post-dispersal seed predators at Peel Forest, the amount of seed preyed upon varies among plant species, and post-dispersal seed predation by mammalian species can lead to differences in seedling richness and abundance. I proved that the influence of exotic mammals on seedling establishment is also linked to habitat structure and recruitment limitations. When combined these observations suggest that exotic mammalian post-dispersal seed predators may play an important role in determining landscape abundance and distribution of plants at Peel Forest.

No description available.