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The studies upon which this thesis is based were designed to evaluate normal fetal and neonatal adaptation and the effects of obstetrical interventions during labor and delivery on fetal and neonatal cerebral circulation. Non-invasive Doppler ultrasound was used to record blood flow velocities from the middle cerebral artery (MCA) both antenatally from the fetus, and from the newborn in the early
Inflammatory bowel disease is thought to result from the inappropriate and ongoing activation of the mucosal immune system driven by the presence of normal luminal flora. In this process monocytes/macrophages contribute to and maintain chronic inflammation by being both regulatory and effector cells. This study aimed at exploring the effects and regulation of chronic inflammation in inflammatory
The terminal differentiation of leukemic cells is closely connected to their death. The concept of differentiation therapy originates from the idea that forced maturation of leukemic cells could induce cell death without the side-effects that are provoked by ordinary chemotherapy. The tumour suppressor protein p53 is a transcription factor, and can induce cell cycle arrest and apoptosis of maligna
During total parenteral nutrition (TPN) adequate nutrition is provided intravenously and the enteral route is bypassed. The integrity of the gastrointestinal (GI) tract, however, is dependent on the passage of food through it. This thesis deals with the effects of TPN on the pancreas and the parotid glands. TPN induced hypotrophy of the exocrine pancreas and the parotid glands. The amylase concent
The control of cultivation conditions and its influence on growth and production have been investigated. The use of fed-batch processes have been demonstrated for several cultivation systems and so has the use of different control signals in these systems. Fed-batch cultivation of Pseudomonas cepacia with on-line measurement and control of the growth rate limiting (toxic) substrate, sodium-salicy
In vertebrates, studies of the aryl hydrocarbon receptor (AhR) have been of particular interest due to its direct involvement in the toxic effects exerted by several environmental pollutants, such as PCB and dioxin. After binding to the toxic molecule, this receptor initiates transcription of several genes that are part of the biotransformation battery but most notably the cytochrome P450 (CYP) ge
High repetition rate laser diagnostics has proven to be a useful tool for studying combustion phenomena. Laser techniques are, in general, relatively non-intrusive and have the potential to measure specific species at very low concentrations and with extremely high temporal resolution. However, most laser systems in this field of research are limited to repetition rates below 100 Hz, and are thus
This thesis explores several novel material systems and innovative device concepts enabled by nanowire technology. State-of-the-art fabrication techniques such as electron beam lithography and atomic layer deposition are utilized to achieve high control and quality in the device fabrication. The devices in this thesis are based on two main types of design geometries, lateral and vertical, each of
The work presented in the thesis covers the use of laser-induced fluorescence (LIF) and photofragmentation laser-induced fluorescence (PFLIF) with short laser pulses to determine species concentrations in different combustion environments. To attain quantitative species concentrations using LIF investigations of the influence of collisional quenching on the fluorescence signal strength is of vital
Biofilms are compact, sessile microbial communities that attach to surfaces in aqueous environments. In wastewater treatment, they are especially important for removal of phosphorus and nitrogen, which, if released into a receiving water body, can cause severe eutrophication. Mathematical models of biofilms in wastewater are used to understand the underlying processes and to describe and analyze b
Some of the main factors affecting the biological removal of nutrients in wastewater treatment plants have been investigated. The influence of low concentrations of dissolved oxygen and the redox potential on the denitrification, activity of activated sludge was studied in batchwise experiments. Oxygen was found to have a negative effect on denitrification even when present at concentrations lower
The anaesthetics we use today dose-dependently decrease the mean arterial pressure partly due to direct or indirect effects on the blood vessels. In the present thesis human omental arteries and veins and rat femoral arteries were investigated in vitro concerning the effects of the intravenous anaesthetic propofol and the volatile anaesthetic sevoflurane on the function of the perivascular sympath
Proliferation, differentiation, and survival of hematopoietic stem cells and multipotent progenitor cells are regulated by cytokines and cell-cell interactions. Kit ligand (KL) and Flt3 ligand (FL) have pleiotropic effects, promotes survival, but are nonredundant. Using myeloid progenitor cell lines and mouse bone marrow-derived Lin- progenitors, we demonstrate that inhibition of phophatidylinosit
N-methyl-2-pyrrolidone (NMP) is an organic solvent widely used in the industry. Irritation of the eyes and in the respiratory system has been reported after occupational exposure to low air levels of NMP. The EU has also classified it as a developmental toxicant. NMP is easily absorbed in the gastrointestinal tract and airways and through skin. The general aim of this thesis was to develop
Cell-signalling via cytokines modulates the local response to surgical trauma, directs the immunologic response and initiates the healing process. Surgical trauma induces a systemic cytokine response and a down-regulation of the antigen presentation capacity of monocytes (HLA-DR expression), which is associated with a poor prognosis if pronounced. The aims with the studies in this thesis were to i
Smooth muscle cells (SMCs) in the vessel wall contract to regulate blood flow and pressure, a function essential for normal circulation through tissues. On the other hand, migration and proliferation of SMCs are important factors in vascular disease, such as atherosclerosis and restenosis following surgical dilatation. The conversion of the SMC to this role is marked by a modulation from contracti
Cholecystokinin (CCK) and the related hormone gastrin have been claimed to exert trophic effects in the pancreas and gastrointestinal tract. Two types of receptors for CCK and gastrin are known to exist, the CCK-A and the CCK-B receptor. They differ in their affinty for CCK and gastrin. The CCK-A receptor has about 500 times higher affinity for sulfated than for non-sulfated CCK and gastrin, while
The studies in this doctoral thesis investigated the concept of touch avoidance. Touch avoidance indicates a person’s negative affect toward physical contact/touch. In study 1 the aim was to develop a questionnaire that measures the level of touch avoidance. The results showed that touch avoidance can be measured along five different dimensions. The results are discussed in relation to attachment
Malaria is a serious disease that causes around 800 000 deaths per year. Current malaria control efforts are hampered by the widespread resistance to common antimalarial drugs, such as the 4-aminoquinoline derivative called chloroquine. Previous research has shown that specific modifications of chloroquine, including inclusion of organometallic fragments into the organic framework, can result in c
