| 1. |
- Hansson, Kristina
(författare)
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Specific Language Impairment in Swedish: Grammar and Interaction
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main purpose of this work was to explore grammar in Swedish children with Specific Language Impairment (SLI), that is children with impaired language development in the presence of normal hearing and otherwise normal development. In four differents studies, spontaneous data from six children with SLI were analysed and compared with data from either younger children with phonological impairment but normal grammar (PI), or from younger controls with typical development. The children with SLI were matched to their controls on the basis of mean length of utterance (MLU). One of the studies also includes longitudinal data. A fifth study includes experimental data from 10 children with SLI and 10 younger language matched controls. The results showed that in particular word order, verb forms requiring an auxiliary or a modal, and subordination were structures where the Swedish children with SLI differed from their controls. The children with SLI were further found to have a higher amount of hesitation phenomena than children with PI. These two groups also differed with respect to qualitative aspects of their maze behaviour. The conversational partner was not found to influence structural aspects of the language production of children with SLI or PI. The conversational partner did, however, influence the interactive behavior and the productivity of the children. Clinically, the pinpointing of vulnerable structures have important implications for the assessment of children with language impairment in Sweden. The analysis of the influence of the conversational partner can have implications for therapy, if further developed. The results point to the importance of investigating SLI in different languages.
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| 2. |
- Persson, Liselott
(författare)
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Cervical Radiculopathy. Effects of Surgery, Physiotherapy or Cervical Collar. A prospective, randomised study.
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The efficacy of surgery, physiotherapy or a cervical collar in the treatment of chronic cervicobrachial pain of radicular origin was evaluated in a prospective, randomised study comprising 81 patients of both sexes, 28-64 years of age, referred for possible neurosurgical treatment. After neurological and radiological examination and giving their informed consent, they were randomised to one of the three treatments. The surgery group underwent anterior decompression and single level fusion by bovine graft. The conservatively treated groups received individual physiotherapy or a rigid cervical collar for three months. The effects were evaluated at three months and 12 months later with respect to pain, tender points, sensory disturbance, muscle strength, neck and shoulder joint mobility, postural control, mood and health status. All treated groups improved, although the improvement rate differed. The surgically treated group was significantly better at three months, but one year later, there was no significant difference between the three groups. The studies variables also included the patients? balance in comparison with a healthy control group and the occurrence of headache. Before treatment, the patients manifested significantly poorer postural control than sex and age- matched controls. Three months after treatment the surgery group showed a significantly improved postural performance and the collar group showed the poorest. Forty-nine of the 81 patients were classified as having cervical headache and 24 of these reported that their headache had improved at the three months? control. Patients with cervical headache reported significantly more cervicobrachial pain and higher tenderness score than patients with cervical radiculopathy with no headache. No one-year follow-up was performed concerning balance and headache. It may be concluded that pain intensity, sensory disturbance, muscle strength and health status can be expected to improve most rapidly after surgery, but a slow improvement with conservative treatments makes the one-year results about equal.
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| 3. |
- Rydén Ahlgren, Åsa
(författare)
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Arterial wall stiffness in man. On gender differences and abnormalities in insulin dependent diabetes mellitus and alpha1-antitrypsin deficiency.
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The mechanical properties of major arteries may reflect early manifestations of vascular disease and are also of interest because they are important for cardiac work. Using echo-tracking sonography and blood pressure measurements, arterial stiffness and diameters were investigated in healthy individuals as well as in patients with insulin dependent diabetes mellitus (IDDM) or alpha1-antitrypsin deficiency (alpha1-AT deficiency). In healthy individuals the stiffness of the abdominal aorta (AO) and the common carotid artery (CCA) increases with age and the diameters increase. These changes are more pronounced in the AO than in the CCA. Further, there are gender differences. This may serve as a background to regional as well as gender differences in the development of vascular disease. In IDDM, stiffness was increased in both the AO and the CCA in women compared to controls. In contrast, there was no difference in stiffness between men with IDDM and controls. Thus, a marked gender-difference in changes of arterial stiffness is found in IDDM. The increased AO stiffness in IDDM women is related to the duration of diabetes. Further, independent of the duration, there is an association between increased AO stiffness and autonomic dysfunction. Increased arterial stiffness in women with IDDM may contribute to the particularly increased risk for cardiovascular complications in diabetic women. To evaluate if alpha1-AT deficiency is a pathogenetic factor in the development of abdominal aortic aneurysm (AAA), the diameter and stiffness of the AO in patients with homozygous alpha1-AT deficiency (PiZZ) were investigated. No difference in the AO diameter compared to controls was found. Men, but not women, had lower AO stiffness than controls. Further, the prevalence of alpha1-AT deficiency (PiZ) in patients with AAA was studied. There was no increase in alpha1-AT deficiency (PiZ) in the patients with AAA compared with the general population. Thus, alpha1-AT deficiency does not seem to be an important pathogenetic factor for the development of AAA.
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| 4. |
- Adner, Mikael
(författare)
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Altered expression of contractile endothelin receptors in the vascular bed
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis aims at characterizing the endothelin (ET) receptors in different vascular beds of man and rat. The ET-A receptor was shown to be the only contractile ET receptor present in all vascular regions, with the exception of the rat mesenteric vein where a weak ET-B receptor-mediated contraction was seen. Treatment with antisense oligodeoxynucleotides to the ET-A receptor mRNA during organ culture showed a decrease of the ET-1-induced contraction in the human temporal artery. However, in human omental arteries there was an increase in response to ET-B receptor agonists together with an increase of ET-B receptor mRNA following organ culture. This phenomenon suggests that contraction is due to upregulation of ET-B receptors. The level of expression of contractile ET-B receptors varies among different vascular regions following organ culture; it is most enhanced in small arteries and veins, whereas it is low or absent in large arteries. The upregulation seems to be most pronounced in the mesenteric region. The culture medium components do not induce upregulation of ET-B receptors, since there was no difference between addition of foetal calf serum or buffer solution. However, when the physiological conditions were altered, by the exclusion of energy supply (glucose) or during culture below normal temperature (at 4 °C), the upregulation was attenuated or totally blunted. This indicates that the phenomenon is a metabolically active process. Experiments with and without endothelium or tension did not alter the level of ET-B receptor expression. This suggests that there is no intrinsic mechanisms that keeps the ET-B receptors at low expression levels. ET-B receptors are shown to be upregulated in several vascular diseases. The use of organ culture can be a very useful tool to study both the function and the regulation of contractile ET-B receptors.
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| 5. |
- Carlsson, Roland
(författare)
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Serum Cholesterol, Lifestyle, Working Capacity and Quality of Life in Patients with Coronary Artery Disease. Experiences from a Hospital-based Secondary Prevention Programme
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Coronary artery diseases (CAD) are main causes of morbidity and hospitalisation in western countries and CAD patients are at considerable risk of suffering further cardiac events. The development and evaluation of secondary prevention programmes therefore an important task. This thesis includes investigations on CAD patients admitted to a secondary prevention programme at Malmö University Hospital, Malmö, Sweden. Four weeks after discharge from the hospital, consecutive male and female patients aged 50 – 70 years with acute myocardial infarction (AMI) or treated with coronary artery bypass grafting (CABG) surgery were randomised to a hospital organised preventive intervention or to usual follow-up at their general practitioners. In the three studies using this randomised design, 87 (study II), 90 (study IV), and 106 (study V) intervention patients were available for evaluation. In addition, without randomisation, lipid levels at four weeks after the event was compared with levels estimated within 24 hours after onset of symptoms in 141 AMI patients (study I), and quality of life (QL) were estimated by questionnaire at one month and at one year after the event in 266 AMI, 94 CABG, and 16 percutaneous transluminal coronary angioplasty (PTCA) patients (study III). The prevention programme was effective in improving food habits but showed no impact on smoking habits or physical exercise in AMI patients (study II). The intervention also did not show any significant improvement in working capacity in AMI and CABG patients. However, working capacity improved in both intervention and reference CABG patients, most probably due to improved coronary circulation from the surgery (study IV). Cholesterol levels decreased significantly in AMI and CABG intervention patients as compared to the corresponding reference patients. This difference most likely was due to a higher frequency of lipid lowering drugs used in the intervention patients (study V). The prevention programme also decreased body mass index significantly in AMI but not in CABG patients (study V). In AMI patients reserving thrombolysis, cholesterol levels estimated within 24 hours after onset of symptoms and at four weeks after the event were virtually equal. In AMI patients not receiving thrombolysis, the lipid estimates from four weeks after the event were slightly, but significantly, above the within 24 hours from onset of symptoms estimates (study I). One month after the event, both somatic and psychological aspects of QL were negatively affected in AMI and CABG patients com--pared to population controls. One year after the event, patients differed from controls mainly in somatic symptoms (study III). Thus, the intervention programme was most successful in affecting lipid levels and food habits in AMI patients. QL was considerably affected in patients following an cardiac event, especially during the initial recovery phase. In addition, in patients receiving thrombolysis, cholesterol levels estimated four weeks after an AMI are reasonably valid estimates of baseline values and may be used to decide about lipid lowering interventions.
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| 6. |
- Eckert, Bodil
(författare)
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Hypoglycaemia: Studies on central and peripheral nerve function.
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hypoglycaemia is an acute complication to insulin-treatment in type 1 diabetes mellitus, which affects many physiological parameters, deteriorates the cognitive function, and may lead to death. The aim of this thesis was to study nerve function, cognitive function and cerebral blood flow during and after hypoglycaemia in healthy subjects and to study certain aspects of a fall in blood glucose in patients with type 1 diabetes mellitus. In paper I, in patients with type 1 diabetes in a poor glycaemic control an insulin-induced rapid fall in blood glucose (18 to 9 mmol/L during 80 min) induced an increased cerebral blood flow by 17%. This is the same response as elicited in healthy subjects when blood glucose is lowered below 2.5 mmol/L, indicating that there was an adaptation to the high blood glucose level in our patients. In papers II and III, the recovery after hypoglycaemia (2.2-2.5 mmol/L) was studied in healthy subjects. The cognitive function was restored at the teast session starting 15 min after normalisation of blood glucose. The cerebral blood flow however remained elevated by 11% 1.5 hours after hypoglycaemia, indicating that cerebral blood flow is regulated by additional factors besides hypoglycaemia. In paper IV, the verve conduction velocity was decreased in the peroneal nerve after hypoglycaemia in healthy subjects, while it was unchanged in the median nerve and in the sural nerve. Hypoglycaemia may thus aggravate the nerve function in diabetes. In paper V, the QT interval in the electrocardiogram (ECG) was measured during and after hypoglycaemia in healthy subjects. The QT interval was prolonged to the upper normal range during hypoglycaemia, which is known to increase the risk for malignant ventricular arrhythmias. In paper VI, a group of cosecutive patients with type 1 diabetes and rapidly progressive severe retinopathy was compared retospectively with patients matched for age and diabetes duration. The patients with severe retinopathy had higher blood glucose level during the recorded 45 months before diagnosis, but the year before the diagnosis of severe retinopathy their blood glucose level decreased significantly to the same level as that of the control group during the observed time period. The year before the diagnosis they had minimal or no retinopathy. It seems plausible, that in these patients the longstanding high blood glucose level had induced retinal blood flow changes and unfavorable metabolic pathways, and that the decrease in blood glucose was detrimental yo yhe neural tissue, not being able to compensate for the relative hypoglycaemia.
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| 7. |
- Nyberg, Lena
(författare)
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Digestion and Absorption of Sphingomyelin from Milk.
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sphingomyelin (SM) is a major component of mammalian cell membranes. Due to its widespread occurrence it is a dietary component, occurring mainly in milk, eggs, meat and fish. In the cell membrane SM was earlier considered to be only a structural element, which interacts with cholesterol and forms a system for bilayer stabilization. In the last decade there has been an increasing interest in sphingolipid metabolism, since hydrolysis products originating from both endogenous and dietary sphingolipids may have important signalling effects and thereby influence cellular functions, such as cell growth, cell differentiation and apoptosis. After some early studies in Lund in the sixties, rather few studies have concerned the digestion and absorption of dietary SM. In this thesis SM isolated from bovine milk was characterized chemically and physically, and used in studies on its intestinal digestion and absorption. SM digestion is extended all over the small intestine and occurs mainly in the middle and lower parts. This coincides with the intestinal distribution of an alkaline sphingomyelinase (SMase), which may be important for digestion. The capacity of SM digestion is limited. Also after administration of small amounts, all of the small intestine and colon are exposed to SM and its metabolites. When rats were fed a mixture of SM and cholesterol, the uptake of both components in the rat intestine was reduced. A novel alkaline SMase has been identified in human bile, with several properties similar to those of the intestinal SMase. In human milk, enzyme activities for the first two steps in the degradation of SM were identified; an acid SMase and an alkaline ceramidase activity. The latter activity was assigned to the bile salt stimulated lipase (BSSL).
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| 8. |
- Elzouki, Abdul-Nasser
(författare)
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Alpha-1-antitrypsin deficiency (PiZ): Clinical studies with special regard to hepatic and vasculitic disorders
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Homozygous alpha-1-antitrypsin (AAT)deficiency (PiZZ) is known to predispose to emphysema and chronic liver disease (CLD). The overall aim of the studies upon which this thesis is based was to investigate extra-pulmonary disease manifestations of AAT deficiency with special reference to hepatic and vasculitic disorders. Both men and women with homozygous AAT deficiency were shown to be at increased risk of cirrhosis (OR=8.3, 42%) and hepatocellular carcinoma (HCC) (OR=5.0, 16%). The risk of HCC was more manifest in men. The risk of cirrhosis or HCC was unrelated to the presence of such environmental factors as alcohol consumption or chronic hepatitis B or C infection. No increased prevalence of viral hepatitis could be found in heterozygous AAT-deficients (PiZ) with CLD, but 63% (5/8) of heterozygotes with hepatitis C infection had severe liver dysfunction. In contrast, a high prevalence of HCV infection was found in patients with low plasma alpha-1-antichymotrypsin (ACT) levels. Among patients with genetic hemochromatosis, 4.5% were found to be homozygous for the PiZ gene, a proportion more than 80-fold greater than that expected in the general population (1/1700) (p<0.0001). The presence of the PiZ gene in these patients contributed to an earlier onset of cirrhosis. A strong correlation was found to exist between systemic necrotizing small-vessel vasculitides and both heterozygous and homozygous AAT deficiency. Vasculitic patients with AAT deficiency were characterized by a more disseminated disease and a worse prognosis. These observations suggest that: 1) although the high risk of cirrhosis and HCC in homozygous AAT-deficients was unrelated to the presence of environmental factors such as alcohol abuse and chronic viral hepatitis, the coexistence of other genetic traits could influence the course of CLD in such individuals; 2) the role of partial ACT deficiency (acquired or hereditary) in hepatitis C is unknown but the protein may have an important defense function; 3) the correlation between AAT deficiency and PR3-ANCA-positive systemic vasculitis suggests AAT to be an important protective protein in vasculitis. When PR3 is exposed on the surface of neutrophils, lack of AAT might cause persistent proteolytic activity and subsequent endothelial cell injury. Vasculitic processes seem to be facilitated by low plasma concentrations of AAT.
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| 9. |
- Kristensen, Bo Traberg, 1952-
(författare)
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Stroke in young adults in northern Sweden
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Objectives. To study different aspects of cerebral venous and arterial occlusive disease including cerebrospinalfluid hydrodynamics, epidemiology, aetiology, genetics, metabolic and haemostatic disorders, andcognitive function in young adults in Northern Sweden.Methods. Cerebrospinal fluid hydrodynamics were investigated with a constant pressure infusion methodin patients with superior sagittal sinus thrombosis. Ten patients were studied with serial examinations, upto 15 years after the onset of the disease.Epidemiological data on ischaemic stroke in young adults aged 18 to 44 years were collected to calculateincidence and mortality based on the WHO Northern Sweden MONICA register of acute strokeevents. One hundred and seven consecutive patients aged 18-44 years with ischaemic stroke referred toUmeå university hospital were studied prospectively during a five-year period and were extensively evaluatedaccording to a standardized protocol. During follow-up at least three months after onset 102 and 80patients, respectively, were evaluated for disturbances in the fibrinolytic system and in the metabolism ofhomocysteine. A comprehensive neuropsychological battery was performed in a subset of 20 patients withinfratentorial infarcts.Results and conclusions. All patients with superior sagittal sinus thrombosis demonstrated a marked increasein intracranial pressure due to raised pressure in the sagittal sinus. A striking feature was the persistentintracranial pressure increase with only a slow decline over time.The incidence rate for ischaemic stroke was higher than previously reported from most countries inWestern Europe. The higher incidence was not explained by a higher prevalence of atherosclerotic vasculopathy. In spite of extensive evaluation, including advanced cardiac imaging, the cause of ischaemic strokein young adults still remains uncertain or unknown in most cases.Patients had lowered tissue plasminogen activator activity and increased plasminogen activator inhibitortype 1 activity. Increased fibrinogen levels and tissue plasminogen activator mass concentration wereindependently associated with ischaemic stroke. Metabolic perturbations were closely interrelated with tissueplasminogen activator and plasminogen activator inhibitor type 1 activity. Elevated plasma fibrinogenlevels and abnormalities in the fibrinolytic system in conjunction with metabolic perturbations may be importantcontributors to an increased stroke risk among young adults.Stroke patients had an exaggerated increase in total homocysteine levels after methionine loading.Abnormal responsivity to methionine loading was associated with higher tissue plasminogen activatormass concentration, plasminogen activator inhibitor 1 levels and lower tissue plasminogen activator activity. Abnormal homocysteine metabolism may provide an additional thrombogenetic risk, partly mediatedby interactions with the fibrinolytic system.Circumscribed infratentorial lesions (mainly cerebellar) impaired central aspects of attention andworking memory, and inflicted damage upon visuospatial skills. In contrast, these patients may not sufferfrom global intellectual impairment and difficulties with respect to memory for previous events. The prognosisis favorable in terms of neurological deficits and handicap, but cognitive disability may be the mostsignificant problem in adapting to their former occupations.Key w ords. Cerebral venous thrombosis, cerebrospinal fluid dynamics, ischaemic stroke, young adults, epidemiology,fibrinolysis, homocysteine, cerebellar infarct, neuropsychology.
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| 10. |
- Malina, Martin
(författare)
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Endovascular Repair of Abdominal Aortic Aneurysms. Aspects on a Novel Technique
- 1998
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A new concept of treating abdominal aortic aneurysms was studied during a three-year period. Instead of open repair, graft insertion was accomplished endovascularly from the groins. The graft was attached by expandable stents to the non-dilated infrarenal aorta, i.e. the aneurysmal neck, and to the iliac artery/ies. Pre- and postoperative work-up included CT-scanning, angiography and ultrasonography on a regular basis. Six papers are included focusing on the fate of the excluded aneurysmal sac and on proximal stentgraft fixation. The median pulsatile wall motion of the sac was postoperatively reduced from 1 mm (I.Q.R 0.8 mm - 1.3 mm) to 0.3 mm (0.2 mm - 0.4 mm) and then remained stable. During the first year, the diameter of the sac was reduced by a median of 6 mm (2 mm 11 mm) but the neck dilated by 2 mm (0.5 - 3.5). Aneurysms with contrast accumulation in the sac (endoleak) were not reduced in size and the wall motion was ~50 % higher than expected. Rigid balloon-expanded stents detached in dilating porcine aortae. Self-expandable stents, on the other hand, complied with the pulsatile motion of the arterial walls and maintained apposition. In animal experiments, aortic stents placed over the renal arteries did not affect renal function and blood flow within one week. In a clinical trial, the proximal, graft anchoring stents, placed across the renal arteries, were not dislodged within six months. The renal function, as assessed by creatinine, CT-scanning, angiography and blood pressure was unaffected. Stents with hooks and barbs penetrating the aortic wall, improved stentgraft fixation tenfold in a cadaveric model.
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