Non-isotropic noise correlation in PET data reconstructed by FBP but not by OSEM demonstrated using auto-correlation function

Background  

Positron emission tomography (PET) is a powerful imaging technique with the potential of obtaining functional or biochemical information by measuring distribution and kinetics of radiolabelled molecules in a biological system, both in vitro and in vivo. PET images can be used directly or after kinetic modelling to extract quantitative values of a desired physiological, biochemical or pharmacological entity. Because such images are generally noisy, it is essential to understand how noise affects the derived quantitative values. A pre-requisite for this understanding is that the properties of noise such as variance (magnitude) and texture (correlation) are known.     

Platelet monoamine oxidase activity in Down's syndrome

The activity of platelet monoamine oxidase in Down's syndrome cases was significantly lower than that of controls. This difference was found for both males and females, and with tyramine, tryptamine and β-phenethylamine as substrate. The K_m values of the monoamine oxidase towards tryptamine as substrate from controls and Down's syndrome patients were similar.     

Association of Campylobacter pylori with induced expression of class II transplantation antigens on gastric epithelial cells

Campylobacter pylori was identified with immunoperoxidase staining and a mouse monoclonal antibody directed against C. pylori in gastric biopsy specimens from 24 patients with gastritis. C. pylori was not found in gastric biopsy specimens from six subjects with histologically normal mucosa. The monoclonal antibody, which was reactive with a surface protein of approximately 20 kilodaltons, was found to be specific for C. pylori, and the immunoperoxidase staining proved to be more sensitive and rapid than culture in detecting the organism. In the tissue specimens where C. pylori was detected with the monoclonal antibody, there was a strong expression of class II transplantation antigens on the epithelial cells and an increased number of T lymphocytes. These findings indicate that C. pylori may initiate local immune responses.     

During hypoxic exercise some vasoconstriction is needed to match O2 delivery with O2 demand at the microcirculatory level.

To test the hypothesis that the increased sympathetic tonus elicited by chronic hypoxia is needed to match O(2) delivery with O(2) demand at the microvascular level eight male subjects were investigated at 4559 m altitude during maximal exercise with and without infusion of ATP (80 mug (kg body mass)(-1) min(-1)) into the right femoral artery. Compared to sea level peak leg vascular conductance was reduced by 39% at altitude. However, the infusion of ATP at altitude did not alter femoral vein blood flow (7.6 +/- 1.0 versus 7.9 +/- 1.0 l min(-1)) and femoral arterial oxygen delivery (1.2 +/- 0.2 versus 1.3 +/- 0.2 l min(-1); control and ATP, respectively). Despite the fact that with ATP mean arterial blood pressure decreased (106.9 +/- 14.2 versus 83.3 +/- 16.0 mmHg, P < 0.05), peak cardiac output remained unchanged. Arterial oxygen extraction fraction was reduced from 85.9 +/- 5.3 to 72.0 +/- 10.2% (P < 0.05), and the corresponding venous O(2) content was increased from 25.5 +/- 10.0 to 46.3 +/- 18.5 ml l(-1) (control and ATP, respectively, P < 0.05). With ATP, leg arterial-venous O(2) difference was decreased (P < 0.05) from 139.3 +/- 9.0 to 116.9 +/- 8.4(-1) and leg .VO(2max) was 20% lower compared to the control trial (1.1 +/- 0.2 versus 0.9 +/- 0.1 l min(-1)) (P = 0.069). In summary, at altitude, some degree of vasoconstriction is needed to match O(2) delivery with O(2) demand. Peak cardiac output at altitude is not limited by excessive mean arterial pressure. Exercising leg .VO(2peak) is not limited by restricted vasodilatation in the altitude-acclimatized human.     

The influence of HLA-A, B compatibility on the outcome of cadaver renal transplantation in Stockholm during 1970–1980

The influence of HLA-A, B-matching on the results of 362 cadaver renal transplantations was analyzed. Of these, 34 of the patients had diabetes and 105 were 55 years old or more. The case material was divided into groups, based on the number of HLA-A, B incompatibilities. The occurence of factors having a possible bearing on kidney graft survival was determined in each match group. It was found that several of these factors, such as the immunosuppressive agents given and the number of high-risk patients, were unequally distributed in the various groups. This may be related to changes in policy that have occured since the transplant unit was moved to Huddinge Hospital in November 1973. In order to obtain homogeneous case material, the Huddinge series was analyzed separately.
A significant difference in survival was found in both materials between transplants with 2 or less incompatibilities and those with more than 2 incompatibilities. A significant difference in patient survival between these two groups was found in the total case material.     

Value appropriation in hepatitis C

The European Journal of Health Economics - In 2015, the Swedish government in an unprecedented move decided to allocate 150 million € to provide funding for new drugs for hepatitis C. This...     

Exposure to natural fluoride in well water and hip fracture: a cohort analysis in Finland.

In the retrospective cohort study based on record linkage, the authors studied a cohort of persons born in 1900-1930 (n = 144,627), who had lived in the same rural location at least from 1967 to 1980. Estimates for fluoride concentrations (median, 0.1 mg/liter; maximum, 2.4 mg/liter) in well water in each member of the cohort were obtained by a weighted median smoothing method based on ground water measurements. Information on hip fractures was obtained from the Hospital Discharge Registry for 1981-1994. No association was observed between hip fractures and estimated fluoride concentration in the well water in either men or women when all age groups were analyzed together. However, the association was modified by age and sex so that among younger women, those aged 50-64 years, higher fluoride levels increased the risk of hip fractures. Among older men and women and younger men, no consistent association was seen. The adjusted rate ratio was 2.09 (95% confidence interval: 1.16, 3.76) for younger women who were the most exposed (>1.5 mg/liter) when compared with those who were the least exposed (< or =0.1 mg/liter). The results suggest that fluoride increases the risk of hip fractures only among women.     

Complications Following Swedish Adjustable Gastric Banding: A Long-Term Follow-up

Background: The Swedish adjustable gastric band (SAGB) has been in use since 1985. The aim of this study was to analyze short and long-term complications linked to the SAGB. Materials and Methods: Between August 1990 and December 1996, we operated on a series of 326 patients (78 men and 248 women) at the Huddinge University Hospital and the Norra ?lvsborg County Hospital. The mean age of patients at surgery was 40 years (range 19-62). The mean preoperative weight was 125 kg (range 81-181). The mean excess weight was 80%. Results: The mean time of follow-up was 28 months (range 6-76). Complications requiring reoperation included two (0.6%) band dislocations, six (1.8%) band leakages, and 16 (4.6%) band migrations-erosions. The most common reason for abdominal reoperation, band migration, was attributed to overfilling of the band system. In the patients in whom migration occurred, the bands had been filled with a mean volume of 12.6 ml fluid. In the remaining patients, the mean volume was 8.7 ml. The most common complication not requiring reoperation was reflux disease (4.7%). In cases with a small pouch, this complication did not seem to be a serious problem. The mean excess weight loss in the 296 patients without complications was 68%. Conclusion: The overall long-term complication rate following SAGB is reasonable. With improved operating technique and closer follow-up, it should be possible to reduce the complication rate further. Reoperation because of band migration appears to be related to overfilling of the system and should therefore be avoidable in most cases.