Comprehensive population-wide analysis of Lynch syndrome in Iceland reveals founder mutations in MSH6 and PMS2.

Lynch syndrome, caused by germline mutations in the mismatch repair genes, is associated with increased cancer risk. Here using a large whole-genome sequencing data bank, cancer registry and colorectal tumour bank we determine the prevalence of Lynch syndrome, associated cancer risks and pathogenicity of several variants in the Icelandic population. We use colorectal cancer samples from 1,182 patients diagnosed between 2000-2009. One-hundred and thirty-two (11.2%) tumours are mismatch repair deficient per immunohistochemistry. Twenty-one (1.8%) have Lynch syndrome while 106 (9.0%) have somatic hypermethylation or mutations in the mismatch repair genes. The population prevalence of Lynch syndrome is 0.442%. We discover a translocation disrupting MLH1 and three mutations in MSH6 and PMS2 that increase endometrial, colorectal, brain and ovarian cancer risk. We find thirteen mismatch repair variants of uncertain significance that are not associated with cancer risk. We find that founder mutations in MSH6 and PMS2 prevail in Iceland unlike most other populations.

Why is colon cancer survival improving by time? A nationwide survival analysis spanning 35 years.

There is limited information present to explain temporal improvements in colon cancer survival. This nationwide study investigates the temporal changes in survival over a 35-year period (1970-2004) in Iceland and uses incidence, mortality, surgery rate, stage distribution, lymph node yield, tumor location and histological type to find explanations for these changes. Patients diagnosed with colon cancer in Iceland 1970-2004 were identified (n = 1962). All histopathology was reassessed. Proportions, age-standardized incidence and mortality, relative, cancer-specific and overall survival and conditional survival were calculated. When comparing first and last diagnostic periods (1970-1978 and 1997-2004), 5-year relative survival improved by 12% for men and 9% for women. At the same time surgery rate increased by 12% and the proportion of stage I increased by 9%. Stage-stratified, improved 5-year relative survival was mainly observed in stages II and III and coincided with higher lymph node yields, proportional reduction of stage II cancers and proportional increase of stage III cancers, indicating stage migration between these stages. Improvement in 1-year survival was mainly observed in stages III and IV. Five-year survival improvement for patients living beyond 1 year was minimum to none. There were no changes in histology that coincided with neither increased incidence nor possibly influencing improved survival. Concluding, as a novel finding, 1-year mortality, which previously has been identified as an important variable in explaining international survival differences, is in this study identified as also being important in explaining temporal improvements in colon cancer survival in Iceland.

Patients' experiences of deep brain stimulation for Parkinson's disease: a qualitative systematic review and synthesis.

OBJECTIVE: To review and synthesise qualitative research studies that have explored patients' experience of deep brain stimulation (DBS) in advanced Parkinson's disease (PD). DESIGN: Systematic review and meta-synthesis of 7 original papers, using metaethnography. SETTING: Studies conducted in Denmark, France and Sweden. PARTICIPANTS: 116 patients who had undergone DBS and 9 spouses of patients. RESULTS: Prior to surgery, the experience of advancing PD is one of considerable loss and a feeling of loss of control. There are significant hopes for what DBS can bring. Following surgery, a sense of euphoria is described by many, although this does not persist and there is a need for significant transitions following this. We suggest that normality as a concept is core to the experience of DBS and that a sense of control may be a key condition for normality. Experience of DBS for patients and spouses, and of the transitions that they must undertake, is influenced by their hopes of what surgery will enable them to achieve, or regain (ie, a new normality). CONCLUSIONS: There is a need for further qualitative research to understand the nature of these transitions to inform how best patients and their spouses can be supported by healthcare professionals before, during and after DBS. In assessing the outcomes of DBS and other treatments in advanced PD, we should consider how to capture holistic concepts such as normality and control. Studies that examine the outcomes of DBS require longer term follow-up.

Acute pancreatitis: a prospective study on incidence, etiology, and outcome.

BACKGROUND AND AIMS: Prospective and population-based studies on the incidence of acute pancreatitis (AP) are lacking. Alcohol consumption has increased considerably in Iceland during the last decade. We aimed to determine the incidence, etiology, severity, and complications of AP and compare the results with a previous study on AP in Iceland. METHODS: A prospective population-based study of patients diagnosed with AP at the National University Hospital of Iceland during 1 year (2010-2011). Information on symptoms, etiology, and complications was registered. RESULTS: During the study period, 134 patients were diagnosed with AP, 78 men (58%), median age 57 years (interquartile range 42-71). Overall, 89/104 (86%) patients had their first attack of pancreatitis, yielding a crude incidence of 40/100 000 inhabitants/year. The major etiological groups were as follows: gallstones, 52 cases (42%); alcohol 29, (23%); postendoscopic retrograde cholangio-pancreatography in 12 (9.5%); medications in eight (6.3%); and idiopathic in 15 (12%). Alcohol was more often the cause in men (25 vs. 4, P<0.05) but the incidence of gallstone-induced pancreatitis was similar in men and women (26 vs. 27). Seven patients had severe complications, three had pancreatic necrosis, two had pseudocysts, and one developed renal failure. Another patient developed acute respiratory distress syndrome and was admitted to the ICU. No patient died of AP during the study period. CONCLUSION: The incidence of AP has not increased significantly in Iceland in the last decade. Alcohol-induced pancreatitis has not increased proportionally despite increased alcohol consumption in Iceland. In a population-based setting, the vast majority of AP is of mild severity.

Indications and surgical outcome following pulmonary metastasectomy: a nationwide study.

AIM: The aim of this retrospective nationwide study was to investigate indications and surgical outcome after pulmonary metastasectomy (PM) in a well-defined cohort of patients and to calculate the proportion of cancer patients who were operated on. METHODS: Between 1984 and 2008, 81 patients (age 54.8 years, 50.6% men) underwent 100 PMs with curative intent in Iceland. For all patients, information on demographics, number of metastases, type of surgery, and complications were collected. Overall survival was estimated with median follow-up of 45 months. For the three most common malignancies, the proportion of patients who underwent PM was calculated using information from the Icelandic Cancer Registry on all cases diagnosed. RESULTS: Of 100 PMs, there were 62 wedge resections, 34 lobectomies, and 4 pneumonectomies. The most common complication was persistent air leakage (>96 hour; 11.1%), and operative mortality was 1.2%. Of the 12 kinds of primary malignancies operated, three were most common: colorectal carcinoma (CRC, n = 27), sarcoma (n = 21), and renal cell carcinoma (RCC, n = 14). The proportion of patients who underwent PM was 1.0% for CRC, 6.5% for sarcoma, and 1.4% for RCC, and their 5-year overall survival was 45.2, 18.6, and 38.5%, respectively (p = 0.11). Survival for all patients was 30.8%. CONCLUSION: The surgical outcome and survival of patients who underwent PM in Iceland are comparable to those in the other studies. Although there was no control group and selection bias cannot be eliminated, the survival of PM patients was better than for the nonoperated patients. However, a relatively small proportion of patients with CRC, RCC, and sarcoma underwent metastasectomy.

Duration of Parkinson disease is associated with an increased propensity for "reinvestment".

BACKGROUND: As a consequence of difficulties in movement initiation and execution, people with Parkinson's disease (PD) are typically encouraged to consciously monitor and control the mechanics of their actions. This is described as 'reinvestment' and has been shown to help mediate effective motor output. Paradoxically, in situations where people with PD are particularly motivated to move effectively, reinvestment may exacerbate existing movement deficits. OBJECTIVE: To examine the propensity for reinvestment in a sample of people with PD. METHODS: A volunteer sample of 55 people with PD was asked to complete a previously validated measure, the Reinvestment Scale. A sub-sample (and age matched controls) was asked to complete a recently developed, movement specific, version of the Scale. Data was collected on Mini Mental State Examination and the Hoehn & Yahr Scale. Participant demographics, including age of onset and duration of disease, were also collated. RESULTS: Multiple regression analyses showed that duration of disease was associated with reinvestment score on both the Reinvestment Scale and the Movement Specific Reinvestment Scale. CONCLUSIONS: Participants appeared to become more aware of the mechanics of their actions over time. Possible explanations for this finding are discussed with reference to rehabilitation.

ALS phenotypes with mutations in CHMP2B (charged multivesicular body protein 2B).

Mutation in the CHMP2B gene has been implicated in frontotemporal dementia. The authors screened CHMP2B in patients with ALS and several cohorts of control samples. They identified mutations (Q206H; I29V) in two patients with non-SOD1 ALS. Neuropathology of the Q206H case showed lower motor neuron predominant disease with ubiquitylated inclusions in motor neurons. Antibodies to p62 (sequestosome 1) showed novel oligodendroglial inclusions in the motor cortex.

Familial risk of colon and rectal cancer in Iceland: evidence for different etiologic factors?

The aim of this study was to characterize the familial risk of colon and rectal cancer using 2 population-based registries in Iceland, the Icelandic Cancer Registry and a genealogy database. The standardized incidence ratio (SIR) was used to estimate the risk among relatives of colorectal cancer index cases diagnosed in Iceland over a 46-year period (1955-2000). The 2,770 colorectal cancer patients had 23,272 first-degree relatives. Among first-degree relatives, there was an increased risk of both colon (SIR 1.47, 95% confidence interval (CI) 1.34-1.62) and rectal cancer (SIR 1.24, 95% CI 1.04-1.47). An increased risk of colon cancer was observed among siblings of colon cancer patients (SIR 2.03, 95% CI 1.76-2.33), whereas no such increase was observed for parents or offspring. Furthermore, the risk of rectal cancer was only increased among brothers (SIR 2.46 95% CI 1.46-3.89) of rectal cancer patients and not among their sisters (SIR 1.0 95% CI 0.40-2.06). The added risk of colon cancer among first-degree relatives was independent of site of colon cancer in the proband. Our results confirm that family history of colorectal cancer is a risk factor for the disease. However, family history has a different association with colon cancer than with rectal cancer, suggesting that the 2 cancer types may have different etiologic factors. Our results have implications for colon and rectal cancer screening programs.

Targeting the subthalamic nucleus for deep brain stimulation: technical approach and fusion of pre- and postoperative MR images to define accuracy of lead placement.

OBJECTIVES: To define the role of magnetic resonance imaging (MRI) and intraoperative electrophysiological recording in targeting the subthalamic nucleus (STN) in Parkinson's disease and to determine accuracy of electrode placement. PATIENTS AND METHODS: We implanted 54 electrodes into the STN in 27 patients. Target planning was done by coordinate guidelines and visualising the STN on MRI and defined in relation to the mid-point of the AC-PC line. Intraoperative microelectrode recording was used. We adjusted electrode positions for placement in the centre of the STN electrical activity and verified this on postoperative MRI in 16 cases, which were fused to the preoperative images to measure actual error in electrode placement in the three axes. RESULTS: Based on coordinate calculation and MRI localisation, the mean of the target was 11.5 mm lateral, 2.5 mm posterior and 4.1 mm inferior to the mid-point of the AC-PC line. Fifty good electrophysiological recordings of the STN (average length 4.65 mm) were achieved and target point adjusted in 90% of lead placements. The mean of the final target after electrophysiological correction was 11.7 mm lateral, 2.1 mm posterior, and 3.8 mm inferior to the mid-point. The distance from the centre of the electrode artefact to the final target used after electrophysiological recording on the fused images was 0.48 mm, 0.69 mm, and 2.9 mm in the x, y, and z axes, respectively. No postoperative MRI related complication was observed. CONCLUSION: Both direct visualisation of the STN on MRI and intraoperative electrophysiological recording are important in defining the best target. Individual variations exist in the location of the STN target. Fewer tracks were required to define STN activity on the side operated first. Our current stereotactic method of electrode placement is relatively accurate.

Loss of heterozygosity at the FHIT gene in different solid human tumours and its association with survival in colorectal cancer patients.

BACKGROUND: Genomic alterations and abnormal expression of the FHIT gene have been reported for a number of cancers. FHIT encompasses FRA3B, the most common fragile site in the human genome, and is suggested to be a candidate tumour suppressor gene. MATERIALS AND METHODS: We analysed and compared the loss of heterozygosity (LOH) pattern in 397 solid human tumours from 9 different locations, using four polymorphic microsatellite markers within the gene (D3S1234, D3S1300, D3S2757 and D3S4260), and two markers (D3S1313 and D3S1600) flanking the gene. In addition, we tested whether there was an association between FHIT LOH and overall patient survival in colorectal cancer. RESULTS: LOH at the FHIT gene affecting at least one of the investigated markers was detected in 166 out of 332 informative tumours, or 50%. The highest detected LOH was in lung tumours (66%) while the lowest was in thyroid and endometrium tumours, (30% and 31%, respectively). Breakpoints were found inside the gene in all tumour types in 12-80% of the tumours with FHIT LOH depending on tumour type, and up to 41% could additionally be located adjacent to the 3' or 5' end of the FHIT gene. Thus we were able to locate breakpoints within or in the vicinity of the FHIT gene in 25-100% of different tumours with LOH. Although not statistically significant, we observed a trend towards a poorer survival of patients with FHIT LOH versus those with retention of heterozygosity. CONCLUSION: Based on our results, LOH of the FHIT gene is a common event in all tumour types analysed with a possible association with poorer survival in colorectal cancer patients. LOH at all markers analysed was, in most of the tumour types, a more common pattern of alterations than breakpoints.

Wilson's disease presenting in a family with an apparent dominant history of tremor.

A patient with Wilson's disease is described who presented with dystonic tremor in a family with an apparent dominant history of tremor. Subsequent investigation showed that the patient's mother had essential tremor, with molecular analysis of the ATP7B gene excluding the possibility of pseudodominant inheritance. This case highlights the importance of considering the possibility of Wilson's disease in every young patient with a movement disorder, even where the clinical picture does not suggest a recessively inherited disorder.

Abnormalities in urinary pterin levels in Rett syndrome.

The pterins, neopterin and biopterin, occur naturally in body fluids including urine. Increased neopterin levels are associated with activation of the cellular immune system and reduced biopterins are essential for biosynthesis of the monoamine neurotransmitters. The present study measured urinary neopterin and biopterin by high-performance liquid chromatography in 40 subjects with Rett syndrome, eight of their healthy sisters and 29 female control volunteers (age range 2-54 years). The results confirm earlier preliminary findings that urinary neopterin levels are raised in a proportion of young girls with Rett syndrome but not in the older women. In contrast urinary biopterin levels are not different from controls in the youngest children but remain low while control values increase with age. These findings may indicate immune activation during the regression phase of Rett syndrome but also raise the possibility that an inherited fault in tetrahydrobiopterin metabolism increases the risk of developing the disorder.

Monitoring of 25-OH vitamin D levels in children with cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis are at risk for malabsorption of fat-soluble vitamins, and those with low 25-OH vitamin D levels have a higher risk of low bone mineral density and long-term skeletal complications. It is currently recommended that vitamins A and E be monitored yearly; however, no recommendations exist for 25-OH vitamin D. Because all three vitamins are fat-soluble, the hypothesis in the current study was that low levels of vitamins A and E could identify patients at risk for low 25-OH vitamin D, so that 25-OH vitamin D measurements could be obtained in only selected circumstances. METHODS: Forty (21 girls) patients with CF, age 10.5 +/- 3.9 (SD) years, were assessed in a cross-sectional survey for ideal weight for height (percentage of predicted), spirometry (percentage of predicted FEV1, 33/40 patients), and serum levels of vitamins A, E, 25-OH vitamin D, and cholesterol (37/40 patients). RESULTS: Nine (22.5%) of 40 patients were malnourished (percentage of predicted ideal weight for height <85%), 7 (21.2%) of 33 had moderate to severe lung disease (FEV1 <60%), 4 (10%) of 40 had low levels of vitamin A, 3 (7.5%) of 40 had low vitamin E levels, 4 (10.8%) of 37 low vitamin E/cholesterol levels, and 4 (10%) of 40 had marginal or low levels of 25-OH vitamin D (<40 mmol/l). The patients with low 25-OH vitamin D were older, with no child < 12 years of age having a 25-OH vitamin D level less than 40 mmol/l. They also had lower vitamin E and vitamin E/cholesterol levels than those with normal 25-OH vitamin D levels. The groups did not differ in percentage of predicted ideal weight for height, lung function, or vitamin A levels. The best positive predictor for 25-OH vitamin D less than 40 mmol/l was low vitamin E (66.7%), with a negative predictive value of 94.6%. 25-OH vitamin D levels correlated with vitamin E/cholesterol levels (r = 0.41, P < 0.01) and weakly with vitamin E levels (r = 0.28, P < 0.08), but not with vitamin A levels. CONCLUSIONS: These results suggest that children aged less than 12 years and older children with normal vitamin E levels are especially unlikely to have low 25-OH vitamin D levels, and this measure can therefore be omitted. In contrast, those children with low vitamin E levels may warrant monitoring.

Urinary levels of neopterin and biopterin in autism.

The pterins, neopterin and biopterin, occur naturally in body fluids including urine. It is well established that increased neopterin levels are associated with activation of the cellular immune system and that reduced biopterins are essential for neurotransmitter synthesis. It has been suggested that some autistic children may be suffering from an autoimmune disorder. To investigate this further we performed high performance liquid chromatography analyses of urinary pterins in a group of pre-school autistic children, their siblings and age-matched control children. Both urinary neopterin and biopterin were raised in the autistic children compared to controls and the siblings showed intermediate values. This supports the possible involvement of cell-mediated immunity in the aetiology of autism.

Postprandial changes in superoxide dismutase activity in subjects with Gilles de la Tourette syndrome and controls.

Erythrocyte measures of copper-zinc superoxide dismutase (CuZnSOD) were performed on 11 subjects with a clinical diagnosis of Gilles de la Tourette syndrome (GTS) and 6 healthy controls at specified intervals throughout the day. There were no significant differences between GTS subjects and controls but in both subjects and controls there was a significant increase in SOD, 75 min postprandially, which decreased to baseline 135 min postprandially. This has implications for the timing of biological samples in future studies of SOD. Possible reasons for the increase are discussed.

[High altitude pulmonary edema at a medium height. A case report]. / Das Höhenlungenödem in mittlerer Höhe. Ein Fallbericht.

A 45-year-old, healthy, well-trained man climbed within 12 hours from 300 m above sea level to a shelter at 2500 m in the Tyrolean Alps. During the following 3 days he undertook ski tours to the surrounding mountains up to 3356 m. On the 4th day he suddenly suffered from headache, coughing and very severe dyspnoea even at rest, accompanied by loss of appetite and the feeling of suffocation. The following day he was rescued by a helicopter and taken to hospital. At the time of admission the patient was severely hypoxaemic (capillary PO2 = 25.7 mmHg), and the chest X-ray revealed signs of bilateral alveolar pulmonary edema localised predominantly in the right lung. High-altitude pulmonary edema (HAPE) was diagnosed because of the typical clinical course. Pulmonary gas exchange normalised within hours, and complete restitution was achieved within 2 days. The chest X-ray was normal on the 4th day after admission. HAPE is a non-cardiogenic pulmonary edema which develops in healthy individuals usually above 3000 m. Among the predisposing factors are rapid ascent, severe physical effort, diminished hypoxic ventilatory response and abnormal fluid balance. The treatment of choice is descent to a lower altitude, administration of oxygen and of nifedipine and expiratory positive airway pressure.

An investigation into the role of reactive oxygen species in the mechanism of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity using neuronal cell lines.

The study of oxygen radical generation and effects during 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) metabolism was undertaken in an in vitro test system. Three neurochemically discrete neuronal cell lines, B50 (cholinergic) and B65 rat cell lines and SKNSH human neuroblastoma (both catecholaminergic), were exposed to MPTP (0-200 microM). Parallel experiments were performed using reagent H2O2, an intermediate which may be generated during MPTP metabolism, to determine whether MPTP and H2O2 had any selectivity of toxicity and whether the mechanisms of cell death were similar. MPTP toxicity was shown to be reduced by monoamine oxidase B inhibitors, pargyline (P < 0.01) and selegiline (P < 0.05), indicating that toxicity was due to metabolism of MPTP rather than the parent compound. Cytotoxicity was also decreased in the presence of antioxidants, most notably in the presence of superoxide dismutase and catalase together (P < 0.01), suggesting that reactive oxygen species (ROS) play a role in MPTP-induced cell death. Attempts to determine the intracellular target for oxidative attack did not identify significant levels of lipid peroxidation products, but did demonstrate nucleoid expansion, possibly the result of double stranded DNA breaks induced by ROS.