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| 2. |
- Ahlsson, Fredrik, 1967-
(författare)
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Being Born Large for Gestational Age : Metabolic and Epidemiological Studies
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Obesity is a major health problem in the Western world. Mean birth weight has increased during the last 25 years. One explanation is that the proportion of large for gestational age (LGA) infants has increased. Such infants risk developing obesity, cardiovascular disease and diabetes later in life. Despite the risk of neonatal hypoglycemia, their postnatal metabolic adaptation has not been investigated. Our data, obtained with stable isotope labeled compounds, demonstrate that newborn LGA infants have increased lipolysis and decreased insulin sensitivity. After administration of glucagon, the plasma levels of glucose and the rate of glucose production increased. The simultaneous increase in insulin correlated with the decrease in lipolysis, indicating an antilipolytic effect of insulin in these infants.We also demonstrated an intergenerational effect of being born LGA, since women born LGA, were at higher risk of giving birth to LGA infants than women not born LGA. Further, the LGA infants formed three subgroups: born long only, born heavy only, and born both long and heavy. Infants born LGA of women with high birth weight or adult obesity were at higher risk of being LGA concerning weight alone, predisposing to overweight and obesity at childbearing age. In addition we found that pregnant women with gestational diabetes were at increased risk of giving birth to infants that were heavy alone. This could explain the risk of both perinatal complications and later metabolic disease in infants of this group of women.To identify determinants of fetal growth, 20 pregnant women with a wide range of fetal weights were investigated at 36 weeks of gestation. Maternal fat mass was strongly associated with insulin resistance. Insulin resistance was related to glucose production, which correlated positively with fetal size. The variation in resting energy expenditure, which was closely related to fetal weight, was largely explained by BMI, insulin resistance, and glucose production. Lipolysis was not rate limiting for fetal growth in this group of women. Consequently, high maternal glucose production due to a high fat mass may result in excessive fetal growth.
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| 3. |
- Ahlzén, Rolf, 1950-
(författare)
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Why should physicians read? : Understanding clinical judgement and its relation to literary experience
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Is literary experience of any practical relevance to the clinician? This is the overall question addressed by this investigation, which starts by tracing the historical roots of scientific medicine. These are found to be intimately linked to a form of rationality associated with the scientific revolution of the 17th century and with “modernity”. Medical practice, however, is dependent also on another form of rationality associated with what Stephen Toulmin calls “the epistemology of the biographical”. The very core of clinical medicine is shown to be the clinical encounter, an interpretive meeting where the illness experience is at the centre of attention. The physician can reach the goals of medicine only by developing clinical judgement. Clinical judgement is subjected to close analysis and is assumed to be intimately connected to the form of knowledge Aristotle called phronesis. In order to explore how literature – drama, novels, poetry – may be related to clinical judgement, a view of literature is presented that emphasizes literature as an invitation to the reader, to be met responsibly and responsively. Literature carries a potential for a widened experience, for a more nuanced perception of reality – and this potential is suggested to be ethically relevant to the practice of medicine. The “narrative rationality” of a literary text constitutes a complement to the rationality pervading scientific medicine. The final step in my analysis is a closer exploration of the potential of the literary text to contribute to the growth of clinical judgement, in relation to the challenges of everyday clinical work. Some of the conditions that may facilitate such growth are outlined, but it is also shown that full empirical evidence for the beneficial effects of reading on the clinician reader is beyond reach.
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- Asker-Árnason, Lena
(författare)
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Narration and reading comprehension in Swedish children and adolescents with hearing impairment
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the present thesis was to explore reading comprehension and narration in children and adolescents with different degrees of hearing impairment (HI). In Study I, reading comprehension was investigated in 16 children with cochlear implants (CI), aged 7-13 years. Over 60% of the investigated children performed at the level of their hearing peers. Reading comprehension was better than expected taking the participants poor phonological skills into consideration. The association between reading comprehension and working memory capacity was robust. Study II was a methodological study, where narrative writing (picture-elicited) was studied using keystroke-logging, which was found to be a valid method for children with typical language developing and NH of 10 years of age and above. The analyses of narratives from 27 children aged 8-12 years, showed several relations between the writing process and the writing product. In Study III, the process and the product in written narration was explored in 18 participants with CI, aged 11-19. When comparing their performance to that of participants with NH, the most prominent difference was that the children and adolescents with CI were less linguistically mature. This was illustrated by a much higher proportion of content words (less function words). Regarding older participants, although they wrote as fast, they used significantly more pause time than participants with NH. In study IV, spoken, as well as written narration was investigated in 20 participants with HI and HA, 10-18 years old. The main finding was that they were less lexically varied than participants with NH. Narration and reading comprehension are important skills for academic success and social inclusion. This thesis clearly indicates that many individuals with HI who are over the age of 10 years clearly lag behind their age peers in complex language activities.
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- Bazargani, Farhan, 1969
(författare)
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Acute inflammation in peritoneal dialysis. Experimental studies in rats. Characterization of regulatory mechanisms.
- 2005
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Ingår i: Swedish Dental Journal. Supplement. - Göteborg : Göteborg University. - 0348-6672. ; 171, s. 1-57
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The predominant problems associated with peritoneal dialysis (PD) are ultrafiltration failure and peritonitis. PD maintains a state of intraperitoneal inflammation that affects the structure and function of the peritoneal membrane, potentially impairing ultrafiltration efficiency. Paradoxically, some PD fluids also have anti-inflammatory properties that may compromise the immune defense against peritonitis. This anti-inflammatory feature is mostly due to the glucose degradation products (GDPs), formed during heat-sterilization and storage of PD fluids. The main purpose of the present thesis was to study regulatory mechanisms behind the acute intraperitoneal inflammatory response in PD in the presence and absence of experimental peritonitis. Rats were exposed to a single dose of heat- or filter sterilized PD fluids either as an i.p. injection or as an infusion through an indwelling catheter, with or without supplementations, or pretreatment of the animals. The dwell fluid was analyzed zero, two and four hours later concerning activation of the complement and coagulation cascades, neutrophil recruitment and respiratory burst, ultrafiltration volumes, cytokine-induced neutrophil chemoattractant (CINC-1), rat mast cell protease 2 (RMCP-2), glucose, urea and histamine concentrations and ex vivo/in vitro intraperitoneal chemotactic activity.Exposure to filter sterilized PD fluid alone induced intraperitoneal complement activation and coagulation, neutrophil recruitment and increased the levels of CINC-1 during the dwell. Intraperitoneal concentrations of the mast cell markers histamine and RMCP-2 changed little during the dwells and did not indicate mast cell activation. Low molecular weight heparin (LMWH) and C5 blockade improved ultrafiltration. Pretreatment with cobra venom factor, known decomplementing agent, blocked the CINC-1 release and the neutrophil recruitment and improved ultrafiltration. In combination with experimental peritonitis, heat sterilized PD fluid compared to filter sterilized, inhibited the CINC-1 release and the recruitment of neutrophils to the peritoneal cavity without affecting the intraperitoneal complement activation.The results of the present thesis indicate that addition of LMWH to the PD fluid improves ultrafiltration, probably by blocking C5a activity. C5 blockade seems to improve ultrafiltration by a mechanism that involves a reduction in glucose transport, possibly by reducing C5 induced vasodilation. Complement activation is an early step in the acute reaction to PD and probably mediates the downstream events that lead to the recruitment of inflammatory cells to the peritoneal cavity. The cells involved in the release of CINC-1 later in this sequence are probably the mesothelial cells. During experimental peritonitis, heat sterilized PD fluids inhibited the neutrophil respiratory burst response of intraperitoneal neutrophils. Heat sterilized PD fluids also inhibit the recruitment of neutrophils to the peritoneal cavity by a mechanism independent of complement activation but probably depending on cytokine CINC-1 release during peritonitis.
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- Berginström, Nils, 1984-
(författare)
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Fatigue after traumatic brain injury : exploring novel methods for diagnosis and treatment
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Traumatic brain injury (TBI) is one of the most common causes of disability and mortality. While some patients recover quickly, especially at the mild side of the injury severity continuum, many will experience symptoms for years to come. In this chronic phase, patients report a wide array of symptoms, where fatigue is one the most common. This fatigue makes huge impact in several areas of these patients’ lives. Despite the prevalence of fatigue after TBI, the underlying mechanisms are unclear. Further, there are no standardized way for assessment and diagnosis, and there are no treatments with satisfying empirical support. The aim of this thesis was to examine the effects of the novel compound OSU6162 on fatigue in patients with TBI, and to explore functional and structural brain imaging correlates of fatigue after TBI.Methods: Studies I and III were based on a placebo-controlled, double-blinded clinical trial examining the effects of the monoaminergic stabilizer OSU6162 on fatigue in patients in the chronic phase of traumatic brain injury. In study I, self-assessment scales of fatigue and neuropsychological tests were used as outcomes, while functional magnetic resonance imaging (fMRI) blood-oxygen-level dependent (BOLD) signal was the primary outcome in study III. Studies II and IV used cross-sectional designs, comparing patients with TBI with age- and gender matched healthy controls. Study II examined whether fMRI BOLD signal could be used to detect and diagnose fatigue in patients with TBI, and study IV whether white matter hyperintensities (WMH) contribute to lower cognitive functioning and presence of fatigue after TBI.Results: Study I revealed no effects of OSU6162 during 28 days of treatment at maximum doses of 15 mg twice daily on measures of fatigue or any other outcome. The results from study II indicated that fatigue after TBI is linked to alterations in striato-thalamic-cortical loops, and suggested that fMRI could be a promising technique to use in the diagnosis of fatigue after TBI. In study III the results revealed effects of treatment in the right occipitotemporal and orbitofrontal cortex. In these areas, the BOLD response was normalized in the OSU6162 group as compared to healthy controls, while the placebo group showed a steady low activity in these areas. The regional effects were located outside the network shown to be linked to fatigue in study II, which might explain why there were no effects on fatigue after treatment with OSU6162 in study I. Study IV showed that WMH lesions increased with increased TBI severity, but the presence and extent of lesions did not explain lower neuropsychological functioning or fatigue in subjects with previous TBI.Conclusions: In summary, although no effects on fatigue after treatment with OSU6162 were seen, the results provide support to the theory that fatigue after TBI is linked to alterations in striato-thalamic-cortical loops, and on how fatigue after TBI could be assessed or diagnosed using fMRI. Structural damage within white matter was however not related to fatigue.
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| 8. |
- Bertilsson, Johan
(författare)
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Human motor control, autonomic and decision processes under physical and psychological stress. Instinctive, reflexive and adaptive aspects.
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The stress response is governed by automatic neurological and hormonal processes that occur before we become consciously aware of a dangerous situation. If stress ensues for 15-30 seconds, the hormonal processes may have progressed so far that recovery takes an hour or longer instead of minutes. Stress can affect our behavior and in certain professions, such as the police force and emergency services, being in stressful situations is routine. When the stress imparted on an action is low, there may be little detriment to performance. However, when the stress imparted on an action is high, performance may be reduced and viewed as unsatisfactory. This thesis has examined the situational characteristics and performance of police officers in stressful incidents where firearms and pepper spray have been used, and during training scenarios designed to induce stress. Pepper spray and firearms were often used differently in real situations, both operationally and technically, compared to the way they were used during training. When armed assailants were encountered in actual incidents, weapons were often used late on and at very short ranges. One real life event studied in detail showed that both police officers and civilian witnesses suffer from similar perceptual and memory distortions. When mimicking real situations for training through simulations, stress levels increased as evidenced by an increase in heart rate which may be used to ensure the closeness of training simulations to real events. When assessing the suitability of pupil dilation as a stress measure, the pupil underwent dilation in spite of large illumination increases, and the pupils also dilated when a threat emerged early in stress-inducing scenarios. Subjective assessments made by six experts separately, rated performance as being impaired in the simulated stress training in addition to poorer performance of a highly trained, complex, motor skill. To conclude, stress can affect police officers during interventions and training, as it impaired perception and memory, cognition, decision-making and the motor skills necessary for equipment and weapon use. Hence, the consequences of stress responses should be considered when designing tactics, training and equipment so that tasks can be carried out well when stress is heightened. An increased understanding of physiological and behavioral changes to stressful situations in police officers will contribute to rationalizing outcomes and influencing policy based on scientific empirical and physiological grounds.
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| 9. |
- Björnstig, Ulf
(författare)
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Snowmobile, motorcycle and moose-car accidents : aspects on injury control
- 1985
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Injuries related to snowmobiles, motorcycles and moose-car collisions have increased. The aim of the present thesis was to analyse mechanisms and consequences in fatal and non-fatal accidents of these types, and to penetrate possible preventive measures.SnowmobilesThe median age of the injured was 30 and of the killed 32, males predominating. A majority of the accidents occurred during weekends, and especially the fatal accidents occurred after dark. The extremities were the most commonly injured parts of the body, however, drowning, crushed chest and cranial injuries caused most of the fatalities. Among the fatalities, four out of five were under the influence of alcohol. The present Swedish laws regarding snowmobiles seem well motivated. "Built-in" safety measures in the construction of the snowmobiles, properly designed snowmobile tracks and functional search and rescue systems could reduce the injuries.MotorcyclesThe median age was 19 years for both the traffic injured and the killed. Half of the traffic accidents were collisions with other motor vehicles. In the fatally injured group, also collisions with fixed roadside objects were common. Of the fatally injured, more than every fifth person died in an accident where alcohol was an influential factor. In the injured group, lower extremity injuries (especially in off-road riding) were common and among the fatalities most riders died from injuries to the head or chest. Out of one thousand motorcycle riders interviewed, 45% reported wobbling experiences (8% reported severe wobbling). Possible injury reducing measures include increasing the licensing age, more discriminating driving test, "built-in" restriction of the motorcycle's top speed, elimination of motorcycles prone to wobbling, and a more intensive traffic supervision (speeding, alcohol).Moose-car collisitionsThe median age of the drivers was 38 years. Most collisions happened at dusk or when dark (3/4). The median collision speed was 70 km/h. The damage to the car was typical, the roof and the windshield pillars were deformed downwards and backwards. The broken windshield was often pressed into the passenger compartment. Most of the injured car occupants suffered cuts predominantly to the head and upper extremities. Nearly all the fatally injured died of head and neck injuries. The injuries may be reduced by strengthening the roof and the windshield pillars, and by introducing anti 1 acerati ve windshields.
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| 10. |
- Bruce, Barbro
(författare)
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Problems of language and communication in children; Identification and intervention
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis addresses identification and intervention of language and communication problems in children. The issue of identification is addressed in study I by investigating communicative ability in 18-month-old children, and in study II by exploring the prevalence of language and communication problems in children with complex problems, such as attention deficit hyperactivity disorder (ADHD). The issue of intervention is addressed in studies III and IV by analysing verbal interaction in conversations, in which one of the participants is a child with specific language impairment (SLI). Study III explores how dialogues between children with SLI and typically developing peers (TLD) representing the same age (age peers), and the same language level (language peers) respectively, differ with respect to responsiveness, assertiveness and reciprocity. Study IV investigates interactional style and elicitation strategies of speech/language pathologists (SLP) during intervention, and how these factors influence the child with SLI. The results from study I show that receptive skills and symbolic play at 18 months of age are significantly associated with language ability three years later. Study II, in which language skills in children with ADHD were explored, indicates that language ability plays an important role for all other aspects of children's development and behaviour, with the exception of motor skills. Use of language and language comprehension caused these children many more problems than structural aspects of language production. Furthermore, reading and writing problems were found to be very frequent. Study III shows that dialogues between children with SLI and TLD age peers are characterized by more responsiveness and topic coherence than dialogues between children with SLI and TLD language peers. However, the children with SLI were more assertive, i.e., introduced more topics, in dialogues with language peers. Study IV indicates that the children with SLI talked more and had a higher mean length of utterance (MLU) in the free conversational context, whereas the individually selected grammatical targets occurred more often in the training context. In the conversational context the SLPs linked, i.e., attended, more to the child's focus and gave more feedback, while in the training context the individually selected grammatical targets occurred more often and the children were more frequently asked to follow instructions. The results have important clinical implications. First; screening procedures at Child Health Care (CHC) centres should be recommended to focus on receptive language skills and play behaviour, and not only on size of vocabulary at 18 months of age. Second; language skills, in particular language comprehension, language use and literacy skills were found to cause children with ADHD problems, and should therefore be assessed. Third; it is of great value for children with SLI to be in mixed groups with peers representing different ages and language levels, and to avoid the risk of not being selected as playmates. Fourth; increased awareness of how interactional style and elicitation strategies influence the developing language skills in children with SLI can be used in intervention planning, depending on the goals of the specific intervention procedures for the individual child.
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