Heart failure and left ventricular dysfunction are major causes of morbidity and mortality. In this thesis, metabolic, hormonal, genetic and prognostic aspects of echocardiographically determined left ventricular function were investigated in a fairly large longitudinal population-based study of men. The participants were examined both at age 50 and 70 years and were followed for mortality using the national cause-of-death registry. Several factors associated with the insulin resistance syndrome predicted left ventricular systolic dysfunction independent of myocardial infarction, hypertension, diabetes and the use of cardiovascular medication after twenty years follow-up. Plasma levels of N-terminal atrial natriuretic peptide (N-ANP) were significantly increased in men with left ventricular dysfunction in comparison to healthy men. However, the diagnostic accuracy was poor due to the extensive overlapping between the groups. Relations between a haplotype of the novel hUNC-93B1 gene and the E/A-ratio were found and validated in separate samples of the cohort. Myocardial performance index (a Doppler derived index of combined left ventricular systolic and diastolic function) and left ventricular ejection fraction were found to be predictors for cardiovascular mortality independent of traditional cardiovascular risk factors in a longitudinal analysis with a mean follow-up of seven years. In conclusion, this thesis showed that left ventricular function is influenced by metabolic, hormonal and genetic factors and that echocardiographic measurements of left ventricular function, such as the myocardial performance index, are strong independent risk factors for cardiovascular mortality in elderly men.

Defects in insulin secretion and insulin action are the major abnormalities in the development of Type 2 diabetes. Hyperinsulinemia is a risk marker for Type 2 diabetes and according to some, but not in all studies also for coronary heart disease (CHD). Conventional insulin assays measure immunoreactive insulin including proinsulin-like molecules. Proinsulin and insulin measured by specific methods, insulin sensitivity measured by the euglycemic insulin clamp and early insulin response after a glucose challenge give more detailed information and may be better estimates of true risk for Type 2 diabetes and CHD. This study examined relationships between proinsulin, insulin, insulin secretion and insulin sensitivity for the development of Type 2 diabetes and CHD. The investigation of the prognostic significance of proinsulin and insulin for the development of Type 2 diabetes and CHD was performed in prospective studies of 50-year and 70-year-old men in a population-based cohort. The results indicated, that increased proinsulin concentrations, was a marker of increased risk for Type 2 diabetes independent of measurements of insulin secretion and insulin sensitivity whereas insulin was not. Proinsulin was shown to be a predictor for CHD mortality and morbidity, respectively, independent of conventional risk factors, whereas insulin was not. Insulin sensitivity measured by the gold standard euglycemic insulin clamp at age 70 was a predictor of CHD morbidity, independently of established risk factors. In summary, these data provide evidence that an increased concentration of proinsulin and not an elevated plasma insulin level per se, that constitutes the association with Type 2 diabetes and CHD and that insulin resistance per se, is associated with CHD risk. / Defekter i insulinsekretionen och insulinkänsligheten i målorganen för insulin är de huvudsakliga orsakerna till utvecklandet av typ-2 diabetes. Förhöjd insulinhalt i blodet indikerar nedsatt känslighet för insulin och är en riskmarkör för typ-2 diabetes men också för hjärt-kärlsjukdom enligt vissa studier. Konventionella insulinmätmetoder är ospecifika och mäter immunoreaktivt insulin som förutom insulin också innehåller ett förstadium till insulin, proinsulin. Proinsulin och specifikt insulin, insulinkänslighet bestämd med hyperglykemisk insulin clamp teknik och tidigt insulinsvar vid sockerbelastning ger en bättre och mer detaljerad och precis information. Dessa variabler kan därför utgöra en bättre prediktor för typ-2 diabetes och hjärt-kärlsjukdom. I denna avhandling har proinsulin, specifikt insulin, tidigt insulinsvar vid sockerbelastning och insulinkänslighet jämförts med varandra som prediktorer för utvecklandet av typ-2 diabetes och hjärt-kärlsjukdom. Två studier har omfattat risken för diabetes och två studier risken för hjärt-kärlsjukdom. Män i medelåldern respektive i högre ålder har studerats. Studierna har utförts i en populations-baserad grupp, en kohort som har sitt ursprung i en stor hälsoundersökning som genomfördes i Uppsala 1970 till 1973. Resultaten visar att proinsulin, i motsats till specifikt insulin, är en riskmarkör för utveckling av typ 2 diabetes, oberoende av insulinkänslighet och tidigt insulinsvar vid sockerbelastning. Vidare har visats att proinsulin i motsats till specifikt insulin är en riskmarkör för död respektive sjuklighet i hjärt-kärlsjukdom, oberoende av de kända riskfaktorerna rökning, högt blodtryck och förhöjt kolesterol. Slutligen har visats att insulinkänsligheten i sig är en riskmarkör för hjärt-kärlsjuklighet oberoende av ovanstående riskfaktorer förutom proinsulin. Sammanfattningsvis visar resultaten i avhandlingen att det snarare är proinsulinhalten och inte insulinnivån i blodet som står för de observerade sambanden med typ 2 diabetes och hjärt-kärlsjukdom. Nedsatt känslighet för insulin i sig är förenat med ökad risk för hjärt-kärlsjukdom.

Oncogenic human papillomaviruses (HPVs) are implicated in 99.7 % of cervical cancer cases but require the co-operation of other factors. To investigate potential genetic risk factors we have typed the HLA class II DRB1 and DQB1 loci in 478 women diagnosed with cervical carcinoma in situ and in 608 age-matched controls. Quantitative measurements of HPV 16, HPV 18/45 and HPV 31 were obtained. The DRB1*1501 and DQB1*0602 alleles were found to increase the risk of HPV 16 infection. Carriers of DRB1*1501 and DQB1*0602 were also shown to have an increased risk of a higher viral load compared to non-carriers. The DRB1*1301 and DQB1*0603 alleles were found to protect from HPV 18/45 and 31 infections as well as resulting in a lower viral load in carriers compared to non-carriers. Women with a high HPV 16, 18/45 or 31 viral load were more prone to long-term infections and women with a low HPV 16 viral load were more prone to short-term infections. Carriers of DRB1*1501 and DQB1*0602 alleles were also shown to have an increased risk of long-term infections compared to short-term infections. We also tested if an HPV susceptibility locus found for epidermodysplasia verruciformis (EV) was also linked to HPV susceptibility in cervical cancer. We did not find any linkage to this locus in a set of 77 families, each with at least three cases diagnosed with cervical carcinoma in situ. Other potential risk factors tested were HPV 16 E6 variants together with a p53 codon 72 polymorphism and HLA class II alleles. We found an association between the E6 L83V variant and the HLA DR4-DQ3 haplotype, as well as an increased frequency of Arg homozygosity of p53 in women infected with the L83V variant. These results show that alleles at HLA class II loci represents risk factors for persistent HPV infection and thereby also contribute to the risk of development of cervical carcinoma in situ.

The overall aim of this thesis was to evaluate the outcome when treating children for displaced femoral fractures with external fixation. In a consecutive and prospective study during the period 1993-2000, 96 children aged 3-15 years with 98 displaced femoral fractures were treated with external fixation and early mobilisation. The mean age was 8.1 years, the mean hospital stay was 8.7 days and the mean treatment time was 61 days. All fractures healed. Minor complications included pin tract infections (18%), clinical insignificant malunions, heterotopic ossification and two re-reductions. Major complications (6%) included two re-fractures after significant trauma and three plastic deformations after premature fixator removal leading to an osteotomy. Radiological evaluation was performed up to one year for the whole group and for a subgroup up to two years. The evaluation showed that malunions were few and prone to remodelling almost completely. Although the fractures were fixated without shortening, as recommended earlier, the overgrowth was far less than expected. Isokinetic muscle strength was measured in both hamstrings and quadriceps in 31 of the patients and compared with 31 matched children without previous injury to the legs. Early mobilisation seems to prevent residual muscle weakness previously shown after treatment with traction or cast for femoral fractures in children. A cost analysis was performed, comparing three different treatment modalities of femoral shaft fractures: traction in hospital, traction in hospital/at home and external fixation. The analysis included both total medical costs and costs for the care provider. The most important factors were days spent at the hospital and the sick leave for the care provider. Treatment that can minimise these factors will contribute strongly to a lowering of health care costs. Conclusion: External fixation of displaced femoral fractures in children can be used as standard treatment in children aged 3-15 years. The treatment provides satisfactory results with a low rate of major complications. Early mobilisation seems to prevent residual muscle weakness. The treatment reduce the number of days in hospital and the number of days of sick leave for the care provider and contributes strongly to lowering health care costs.

This dissertation has two parts. Firstly, satisfaction with life as a whole and with 10 life domains (using an instrument termed LiSat-11 with 6-graded scales) is described in a nationally representative sample aged 18-64 years (n: 2,533) and is related to some socio-demographic circumstances. Secondly, vocationally disabled people (n: 109) at an employability institute are prospectively followed in order to determine their life satisfaction and to identify early predictors of vocational rehabilitation outcome. <u>Main results</u>: Gender independently, 70 % of the national sample were satisfied with life as a whole (were happy). The ten domains formed a 4-factor pattern: ”Closeness, Health, Spare time, Provision”. Seven domains were sizeable predictors of overall life satisfaction. In a complex manner socio-demographics were predictive of (gross levels) all LiSat-11 items. Main predictors were perceived health, immigrant status and educational level. Generally, the vocational rehabilitees had low LiSat-11 levels except for the closeness items. They had relatively poor background resources (low “sense of coherence“ level) for successful coping. Whereas a positive rehabilitation outcome was accompanied by increases in several LiSat-11 aspects, only satisfaction with the vocational situation was clearly responsive. Three early predictors of outcome were identified: belief in vocational return, educational level and sense of coherence. <u>In summary</u>: Besides providing reference values for the LiSat-11 instrument, this dissertation demonstrates that different socio-demographic factors influence different areas of concern (domains) in 18- to 64-year-old Swedes. In turn, satisfaction derived from different areas heavily influences level of overall life satisfaction. Moreover, the vocational rehabilitees generally seemed to be predisposed to being poor copers, possibly a major background of low levels of many LiSat-11 aspects. The identified set of predictors of the outcome of vocational rehabilitation emphasizes a need for focusing on psycho-social aspects within vocational rehabilitation.

Physicians are supposed to act as sick-listing experts and they possess a role as gate-keepers to the social insurance system. Earlier studies have demonstrated variation between physicians and physician categories regarding sick-listing practice. In addition to the patient's disease and its severity, a number of other factors may be expected to influence sick-listing practice. Most earlier studies have focused on the patient's disease and his or her work place as cause for sickness absence. The aims of this study were to analyse variation of sick-listing practice between physician categories and the influence of physician characteristics on sick-listing practice, the influence of structure, organisation and remuneration of health care on physician sick-listing practice, the influence of local structural factors in the community, and the influence of a legislative change on physician sick-listing practice. The study was conducted as a cross-sectional epidemiological study of 57563 doctors’ certificates for sickness absence, received by 28 local social insurance offices in eight Swedish counties, during four months in 1995 and two months in 1996. Patient age, sex, and diagnostic group, issuing physician category, presence of a hospital in the municipality, municipality population size and county were all significantly and independently correlated to number of net days of sick-listing. Physician characteristics, such as age, sex and degree of specialisation were all associated with number of net days of sick-listing. Physicians working in general practice issued significantly shorter periods of sick-listing than the other physician categories. Reimbursement of general practice and participation in financial co-operation with social insurance were significantly correlated to length of sickness episode issued by general practitioners. A legislative change performed during the study period was associated with small effects in sick-listing practice. In conclusion, a number of factors other than disease and disease severity and other patient and physician linked factors were found to influence the variation of sick-listing practice. It appears that the closer the influencing factor was to the place were the decision was taken, i.e., the patient-physician consultation, the higher the impact on the decision appeared to be.

The present work is analyzing the general biomechanical aspects of fixation techniques in the upper and lower cervical spine along with clinical implications. The in vitro biomechanical properties of five different posterior atlanto-axial fixation techniques are compared. They provided for either a one, two or three-point fixation between atlas and axes. A new device, the C1 claw was biomechanically tested, which allow for fixation without the need for a structural bone graft. The three-point reconstructions indicated superior biomechanical properties compared to all others. The new C1 claw device was clinically evaluated in a series of 26 patients treated with a posterior C1-C2 fusion. There were no clinical or radiological failures in the series, Twenty-one patients out of twenty-three with any length of follow up either showed a solidly healed fusion or a healed fracture. Distractive flexion (DF) injuries in the lower cervical spine treated with anterior plate alone were analyzed with respect to healing rate and complications in a consecutive series of 36 patients. Results indicated that DF injury stage 1 and 2 according to Allen and Ferguson healed without complication, whereas DF injuries stage 3 had a high frequency of failure, needing an additional posterior fixation. The in vitro biomechanical properties of four different fixation techniques for a distractive flexion injury stage 3 were analyzed. The result indicated that anterior plate alone for fixation of a DF injury stage 3 is insufficient supporting the clinical finding in the previous study. Adjacent level motion was analyzed following a one segment fusion in the lower cervical spine. Motion was found to increase in adjacent levels possibly contributing to accelerated degeneration.

The blood vessels of the pancreatic islets are of crucial importance for oxygen and metabolite supply as well as dispersal of secreted hormones. In addition to this, endothelial cells have an important role in the revascularization process after islet transplantation. Previous studies have reported signs of poor engraftment of transplanted islets, presumably due to impaired revascularization. The aims of this thesis were to investigate the revascularization process of transplanted islets and to examine the role of islet endothelial cells. In this context, the lectin Bandeiraea simplicifolia was found to stain endothelium of both endogenous and transplanted pancreatic islets. By using this lectin we investigated the vascular density of both endogenous and islets transplanted syngeneically beneath the renal capsule, into the spleen or intraportally into the liver of normoglycemic C57BL/6 mice. One month post-transplantation, a time point when the grafts are assumed to be completely revascularized, the vascular density was decreased at all three implantation sites when compared to endogenous islets. Furthermore, most of the blood vessels were located in the graft connective tissue stroma. Similar results were obtained when islet transplant vascular density was determined six months post-transplantation and in cured diabetic animals after one month. In order to evaluate the function of intraportally transplanted islets, we developed a method to retrieve such islets. We treated the implantation organ (liver) first enzymatically (collagenase) and then mechanically, thereafter we could re-isolate the transplanted islets for further in vitro studies. The retrieved islets had a decreased insulin relase, insulin content and glucose oxidation rate when compared to non-transplanted control islets. To understand the role of islet endothelium in the revascularization of transplanted islets we performed angiogenesis GEArray studies on islet endothelial cells, from non-cultured, cultured and transplanted islets. We found that the islet endothelium expressed mRNA for both inhibitors and inducers of angiogenesis, and that this expression differed with time. The functional consequences of this remain to be determined. In summary, the results presented above provide a useful platform for future studies of the morphology and function of islet endothelial cells, especially with a view for elucidating changes induced by islet transplantation.

Cardiopulmonary bypass (CPB) is associated with inflammatory response and activation of coagulation. Heparin coating of the CPB circuit is shown to improve the biocompatibility of the surface. The biological effects of a new heparin surface, the Corline Heparin Surface (CHS), prepared according to a new principle, have been studied. The CHS used during coronary artery bypass grafting with CPB in sixty patients prevented adhesion of cells to the extracorporeal device. The activation of inflammation, coagulation, and fibrinolysis was significantly reduced by the use of CHS. Both a reduced and an increased dose of systemic heparin in combination with the heparin-coated surface resulted in more activation of inflammation and coagulation. Photoelectron spectroscopy studies of the molecular structure of the CHS demonstrated that a single layer of the heparin surface, equivalent to what was used in the in vivo studies, did not completely cover the substrate surface. Additional layer of immobilized heparin has resulted in a complete coverage. We examined the biological effects, i.e. activation of inflammation and coagulation, by CHS in one and two layers in an in vitro-study. The data from this study clearly demonstrated that a uniform surface coating of the CHS results in only minor activation of coagulation, inflammation and cell activation. Monocytes do not normally express tissue factor (TF), initiator of the coagulation in vivo, but can be induced upon adhesion to artificial surfaces. TF is receptor for coagulation factor VIIa (FVIIa) and binding subsequently leads to formation of thrombin. Other biological effects beyond coagulation, as inflammation and angiogenesis, has recently been associated with the formation of TF·FVIIa. The TF∙FVIIa signal transduction induced an increased sensitivity to PDGF-BB-stimulated migration and an increased production of IL-8 and TNF-α in monocytes. These could be important mechanisms for continued recruitment of cells to sites of inflammation.

No description available.