Ischemic Stroke in Adults With Congenital Heart Disease: A Population-Based Cohort Study.

Background Congenital heart disease (CHD) is associated with risk factors for ischemic stroke including cardiac arrhythmias and heart failure. However, few long-term follow-up data exist on ischemic stroke risk and associated mortality in adults with CHD. Methods and Results Using Danish nationwide registries, we identified individuals aged ≥18 years diagnosed with CHD, at any age, from 1963 to 2017 and a sex and birth year-matched (1:10) general population comparison cohort. We computed risks, as well as sex and birth year-adjusted hazard ratios (aHRs) for ischemic stroke and 30-day post-stroke mortality in CHD adults compared with the general population. Analyses were stratified according to age <60 years (young) and ≥60 years (older). We identified 16 836 adults with CHD. The risk of ischemic stroke at age 60 years was 7.4% in the CHD cohort and 2.9% in the general population cohort. The adjusted hazard ratios for ischemic stroke compared with the general population was 3.8 (95% CI: 3.3-4.3) in young CHD adults and 1.6 (95% CI: 1.4-1.9) in older CHD adults. The adjusted hazard ratios for post-stroke mortality compared with the general population was 2.3 (95% CI: 1.2-4.4) in young CHD adults and 1.3 (95% CI: 0.9-1.9) in older CHD adults. Conclusions Both younger and older CHD adults have an increased risk of ischemic stroke and by 60 years of age 7.4% of CHD adults will have had an ischemic stroke. Post-stroke mortality was also increased in CHD adults compared with the general population.

Sporadic Creutzfeldt-Jakob Disease in a Woman Married Into a Gerstmann-Sträussler-Scheinker Family: An Investigation of Prions Transmission via Microchimerism.

This is the first report of presumed sporadic Creutzfeldt-Jakob disease (sCJD) and Gerstmann-Sträussler-Scheinker disease (GSS) with the prion protein gene c.305C>T mutation (p.P102L) occurring in one family. The father and son were affected with GSS and the mother had a rapidly progressive form of CJD. Diagnosis of genetic, variant, and iatrogenic CJD was ruled out based on the mother's clinical history, genetic tests, and biochemical investigations, all of which supported the diagnosis of sCJD. However, given the low incidence of sCJD and GSS, their co-occurrence in one family is extraordinary and challenging. Thus, a hypothesis for the transmission of infectious prion proteins (PrPSc) via microchimerism was proposed and investigated. DNA from 15 different brain regions and plasma samples of the CJD patient was subjected to PCR and shallow sequencing for detection of a male sex-determining chromosome Y (chr. Y). However, no trace of chr. Y was found. A long CJD incubation period or presumed small concentrations of chr. Y may explain the obtained results. Further studies of CJD and GSS animal models with controlled genetic and proteomic features are needed to determine whether maternal CJD triggered via microchimerism by a GSS fetus might present a new PrPSc transmission route.

Incidence and Mortality of Adults With Pulmonary Hypertension and Congenital Heart Disease.

Reports on pulmonary hypertension (PH) in the aging congenital heart disease (CHD) population are few and focused on arterial PH and patients with systemic-to-pulmonary shunts. Our objective was to estimate incidence and mortality of adult-onset PH in the CHD population. Using Danish nationwide registries, we identified all patients diagnosed with CHD from 1963 to 1974 and 1977 to 2012. Patients were matched 1:10 by birth year and gender with general population subjects. Between 1977 and 2013 adults >18 years of age were followed up until PH diagnosis, death, or emigration, whichever came first, using data from the Danish National Registry of Patients. We computed cumulative incidences of PH. Using Cox regression, we compared the mortality rate between CHD subjects with and without PH matched by gender and birth year. We identified 14,860 patients with CHD. At 70 years of age, their overall cumulative incidence of PH was 7.2% (8.3% in those with systemic-to-pulmonary shunts and 5.3% in those without) compared with 0.4% in the general population. The 1-, 5-, and 10-year mortality for adults with CHD and PH was 24%, 44%, and 52%, respectively. This represented a 4-fold (95% confidence interval 3.3 to 5.6) increase in mortality compared with adults with CHD without PH after adjusting for gender, birth year, CHD severity, and presence of extracardiac defects. In conclusion the incidence of PH was substantially increased in adults with CHD relative to the general population. Of note, the increased incidence was not limited to those with a history of systemic-to-pulmonary shunts. PH was associated with increased mortality.

Risk of Dementia in Adults With Congenital Heart Disease: Population-Based Cohort Study.

BACKGROUND: More children with congenital heart disease (CHD) are surviving to adulthood, and CHD is associated with risk factors for dementia. We compared the risk of dementia in CHD adults to that of the general population. METHODS: In this cohort study, we used medical registries and a medical record review covering all Danish hospitals to identify adults with CHD diagnosed between 1963 and 2012. These individuals with CHD were followed from January 1, 1981, 30 years of age, or date of first CHD registration (index date for matched members of the general population cohort) until hospital diagnosis of dementia, death, emigration, or end of study (December 31, 2012). For each individual with CHD, we identified 10 members of the general population utilizing the Danish Civil Registration System matched on sex and birth year. We computed cumulative incidences and hazard ratios (HRs) of dementia, adjusting for sex and birth year. RESULTS: The cumulative incidence of dementia was 4% by 80 years of age in 10 632 adults with CHD (46% male). The overall HR comparing adults with CHD with the general population cohort was 1.6 (95% confidence interval [CI], 1.3-2.0). The HR among individuals with CHD without extracardiac defects was 1.4 (95% CI, 1.1-1.8). Adults with mild-to-moderate CHD had an HR of 1.5 (95% CI, 1.1-2.0), whereas the HR was 2.0 (95% CI, 1.2-3.3) for severe CHD, including univentricular hearts. The HR for early onset dementia (<65 years of age) was 2.6 (95% CI, 1.8-3.8), whereas the late-onset HR was 1.3 (95% CI, 1.0-1.8). CONCLUSIONS: CHD was associated with an increased risk of dementia compared with the general population, in particular for early onset dementia. Further understanding of dementia risk in the population with CHD is a potential target for future investigation.

Myocardial Infarction in Adults With Congenital Heart Disease.

We compared the incidence and 30-day mortality of myocardial infarction (MI) in adults with congenital heart disease (CHD) relative to the general population. This cohort study used nationwide population-based medical databases to identify individuals born before 1982 and diagnosed with CHD in Denmark between 1963 and 2012. Patients were followed for first-time MI using data from the Danish National Registry of Patients. For each subject with CHD, we identified 10 controls from the general population, matched by sex and birth year. A unique personal identifier enabled follow-up for migration, death, or MI. We computed cumulative incidences and hazard ratios (HR) adjusted for birth year and sex for MI and 30-day mortality after MI. We identified 10,501 CHD adults alive at 30 years. By 70 years of age, the cumulative incidence of MI was 10% versus 6.5% for controls. The overall HR of MI in subjects with CHD compared with controls was 2.0 (95% CI 1.7 to 2.3). The 30-day mortality was 18% for the 296 subjects with CHD experiencing an MI during follow-up. The overall HR comparing 30-day mortality after MI between subjects with CHD and controls was 1.4 (95% CI 1.0 to 1.8). The greatest mortality was observed in adults with severe CHD (HR 2.7 [95% CI 1.5 to 5.0]). In conclusion, the incidence of MI and the 30-day mortality after MI for severe CHD were increased in adults with CHD compared with the general population. Underlying mechanisms need to be clarified.

Congenital Heart Disease With and Without Cyanotic Potential and the Long-term Risk of Diabetes Mellitus: A Population-Based Follow-up Study.

BACKGROUND: Long-term survival for persons born with congenital heart disease (CHD) is improved, but limited knowledge exists of this growing population's acquired cardiovascular risk profile. This study's purpose was to assess CHD survivors' risk for type 2 diabetes mellitus (T2DM) with attention to the impact of cyanotic CHD. METHODS AND RESULTS: This population-based cohort study included Danish subjects with CHD who were born between 1963 and 1980 and were alive at age 30 years. For each CHD case, we identified 10 individuals from the general population matched by sex and birth year, by using the Danish Civil Registration System. Complete follow-up was obtained through Danish public registries for death, emigration, and T2DM (diagnosis and prescriptions record). We computed cumulative incidences and hazard ratios of developing T2DM after age 30 for 5149 CHD subjects compared with the general population. After adjusting for CHD severity, as well as age, sex, preterm birth, and extracardiac defects, we analyzed the impact of cyanotic compared with acyanotic CHD. By age 45 years, the cumulative incidence of T2DM after age 30 was 4% among subjects with CHD. Subjects with CHD were more likely to develop T2DM than the general population (hazard raio 1.4, 95% CI 1.1-1.6). Subjects CHD who had cyanotic defects were more likely to develop T2DM than were subjects with acyanotic CHD (hazard ratio 1.9, 95% CI 1.1-3.3). CONCLUSIONS: CHD survivors had an increased risk of developing T2DM after age 30. Patients with cyanotic CHD are at particular risk. Given the cardiovascular health burden of T2DM, attention to its development in CHD survivors seems warranted.

VEGF-A mRNA measurement in meningiomas using a new simplified approach: branched DNA and chemiluminescence.

For decades, the preferred and almost sole method for measurement of gene expression has been RT-qPCR. The method is robust, inexpensive, and well-studied; however, PCR is also quite laborious and vulnerable to contamination. As part of an investigation of VEGF-A gene expression in meningiomas, an alternative and less laborious method for gene expression analysis based on branched DNA hybridization and chemiluminescence (Lumistar) was tested. Albeit the two methods differ, in principle, cellular mRNA-concentration is measured with both. Because they both determine gene expression via the measurement of mRNA-concentration, they were expected to be comparable. The aim of the present study was to compare Lumistar to the traditional RT-qPCR approach in a routine laboratory setting, where there is emphasis on rapid analysis response. Meningioma (n = 10) and control brain tissue (n = 5) samples were collected and VEGF-A and GAPDH mRNA were quantified using both RT-qPCR and Lumistar. Furthermore, two dilution series of two of the meningioma samples were prepared in order to make quantitative analyses. Both Lumistar and RT-qPCR-results were found to follow concentration dependent linear paths when diluted (p < 0.0001 and p < 0.01). Finally, Lumistar and RT-qPCR analyses were performed with the inclusion of a reference gene (GAPDH), where similar results were obtained with the two methods (R2 = 0.48; p = 0.01). It is intriguing that in spite of the vast difference in handling and assay principles, gene expression results are similar. The preferred method depends on the variability of the samples, budget, and time. Lumistar was less time consuming, while RT-qPCR was less expensive and best suited for data sets with large sample variability.

Long-Term Nationwide Follow-Up Study of Simple Congenital Heart Disease Diagnosed in Otherwise Healthy Children.

BACKGROUND: Systematic follow-up is currently not recommended for patients with simple congenital heart disease; however, only a few data exist on the long-term prognosis of simple congenital heart disease. METHODS AND RESULTS: We undertook a nationwide follow-up study of a cohort of 1241 simple congenital heart disease patients, diagnosed from 1963 through 1973, in otherwise healthy children and alive at 15 years of age. We identified 10 age- and sex-matched general population controls per patient. We followed the study population through Danish public registries from the age of 15 years up to January 1, 2013 with respect to mortality, cause of death, morbidity, and medical follow-up. The patients were followed for a total of 58 422 patient-years and had a median age at the end of follow-up of 47.4 years (interquartile range, 43.5-50.9). Mortality was increased compared with the general population, both overall (adjusted hazard ratio [aHR],1.9; 95% confidence interval [CI], 1.5-2.4)] and for patients (79%) without medical follow-up (aHR, 1.7; 95% CI, 1.3-2.2). The most common cause of death (40%) was sudden unexpected death (aHR, 4.3; 95% CI, 2.9-6.5). The incidence of critical cardiac morbidity was 3.9 per 1000 patient-years with the most frequent events being an adult (re)operation and hospitalization for heart failure or ventricular tachyarrhythmia. This corresponded to an aHR of 5.7 (95% CI, 4.6-6.9) when compared with the general population. CONCLUSIONS: Patients diagnosed with simple congenital heart disease in the 1960s have substantially increased long-term mortality and cardiac morbidity compared with the general population. Further studies on the effectiveness of systematic medical follow-up programs appear warranted.

Aberrant expression of miR-218 and miR-204 in human mesial temporal lobe epilepsy and hippocampal sclerosis-convergence on axonal guidance.

OBJECTIVE: Mesial temporal lobe epilepsy (MTLE) is one of the most common types of the intractable epilepsies and is most often associated with hippocampal sclerosis (HS), which is characterized by pronounced loss of hippocampal pyramidal neurons. microRNAs (miRNAs) have been shown to be dysregulated in epilepsy and neurodegenerative diseases, and we hypothesized that miRNAs could be involved in the pathogenesis of MTLE and HS. METHODS: miRNA expression was quantified in hippocampal specimens from human patients using miRNA microarray and quantitative real-time polymerase chain reaction RT-PCR, and by RNA-seq on fetal brain specimens from domestic pigs. In situ hybridization was used to show the spatial distribution of miRNAs in the human hippocampus. The potential effect of miRNAs on targets genes was investigated using the dual luciferase reporter gene assay. RESULTS: miRNA expression profiling showed that 25 miRNAs were up-regulated and 5 were down-regulated in hippocampus biopsies of MTLE/HS patients compared to controls. We showed that miR-204 and miR-218 were significantly down-regulated in MTLE and HS, and both were expressed in neurons in all subfields of normal hippocampus. Moreover, miR-204 and miR-218 showed strong changes in expression during fetal development of the hippocampus in pigs, and we identified four target genes, involved in axonal guidance and synaptic plasticity, ROBO1, GRM1, SLC1A2, and GNAI2, as bona fide targets of miR-218. GRM1 was also shown to be a direct target of miR-204. SIGNIFICANCE: miR-204 and miR-218 are developmentally regulated in the hippocampus and may contribute to the molecular mechanisms underlying the pathogenesis of MTLE and HS.

Towards an age-dependent transmission model of acquired and sporadic Creutzfeldt-Jakob disease.

INTRODUCTION: Sporadic Creutzfeldt-Jakob disease (sCJD) might be transmitted by surgery. The purpose of this study was to investigate potential susceptibility to sCJD from surgery at juvenile age and in early adulthood. METHODS: From Danish and Swedish national registries we identified 167 definite and probable sCJD cases with onset from 1987 through 2003, and 835 age-, sex- and residence-matched controls along with their surgical histories. Main, anatomically or etiologically classified surgical procedures followed by a ≥20-year lag were analyzed using logistic regression, and stratified by age at first-registered surgical discharge. RESULTS: The risk of having a diagnosis of CJD depended strongly on age at first surgery with odds ratio (OR) of 12.80 (95% CI 2.56-64.0) in patients <30 years, 3.04 (95% 1.26-7.33) in 30-39 years, and 1.75 (95% CI 0.89-3.45) in ≥40 years, for anatomically classified surgical procedures. Similar figures were obtained for etiologically classified surgical procedures. CONCLUSIONS: Risk of surgical-acquired sCJD depends on age at exposure; this pattern is similar to age-specific profiles reported for CJD accidentally transmitted by human pituitary-derived growth hormone and susceptibility curves for variant CJD estimated after adjustment for dietary exposure to bovine spongiform encephalopathy. There might be an age-at-exposure-related susceptibility to acquire all CJD forms, including sCJD from routine surgery.

[Myopathy causing acute tetraparesis in the intensive care unit]. / Myopati som årsag til akut opstået tetraparese på en intensivafdeling.

This is a case report of a 52-year-old woman with acute respiratory distress who shortly after admission to the intensive care unit developed flaccid tetraparesis with areflexia and elevated serum creatine kinase concentration. Typical clinical presentation, clinical neurophysiological examination and histology confirmed the presence of a necrotizing severe myopathy known as "myopathy with thick fibre loss", a serious but also most often spontaneously reversible condition.

Late-in-life surgery associated with Creutzfeldt-Jakob disease: a methodological outline for evidence-based guidance.

BACKGROUND: There is increasing epidemiological evidence of etiological links between general surgery and sporadic Creutzfeldt-Jakob disease (sCJD) with long incubation periods. The purpose of this study was to identify specific surgical procedures potentially associated with sCJD to be targeted for preventive presurgical-intervention guidance. RESULTS: We propose a three-step clinical guidance outline where surgical procedures associated with sCJD clinical onset - potentially more contaminant - are taken into account. Data on hospital discharges and surgical procedures were obtained from Danish and Swedish national in-patient hospital registries for 167 sCJD cases, onset 1987-2003, and for 835 matched and 2,224 unmatched population controls. Surgery was allocated to different life-time periods as previously reported, and frequencies were compared using logistic regression analysis. In the year preceding clinical onset, persons with sCJD underwent a statistically significant higher number of minor surgical interventions (OR (95% CI): 17.50 (3.64-84.24)), transluminal endoscopies (OR: 2.73 (1.01-7.37)) and gastrointestinal operations (OR: 3.51 (1.21-10.19)) compared to matched controls. Surgical discharges clustered towards clinical onset. These differences increased during the clinical period, with statistically significant higher frequencies for both endoscopies and minor surgery (OR: 13.91 (5.87-32.95), and for main surgical procedures (OR: 2.10 (1.00-4.39)), particularly gastrointestinal surgery (OR: 6.00 (1.83-19.66)), and surgery contacting skeletal muscle. Comparisons with unmatched controls yielded similar results for neurosurgery in the clinical period (OR: 19.40 (2.22-168.34)). CONCLUSIONS: These results suggest that some types of surgical procedures are associated with sCJD, after clinical onset or particularly just before onset. Selective planning of such surgery to minimize instrument/device contamination or quarantining might be feasible. Conditional to progress in sCJD etiological research, results are relevant for guidance development.

Localization of A11-reactive oligomeric species in prion diseases.

AIMS: To investigate in prion diseases the in-situ localization of prion protein oligomers sharing a common epitope with amyloid oligomers involved in a range of neurodegenerative diseases. METHODS AND RESULTS: We performed immunohistochemistry on sporadic Creutzfeldt-Jakob disease (sCJD) (n = 9) and hereditary Gerstmann-Sträussler-Scheinker disease (GSS) (n = 1) specimens with the anti-oligomer antibody A11 to determine the localization of reactive species. We found that A11 reactivity in the sCJD specimens was localized to the cerebral and cerebellar cortices both in spongiform and adjacent, non-spongiform areas, reminiscent of multicentric or diffuse plaques. In the GSS specimens, we found that staining was closely associated with kuru-like plaques, and that A11-reactive species colocalized with protease-resistant prion protein (Prp(Sc)). We also observed sporadic neuronal cytosolic staining in both types of specimen. CONCLUSIONS: We confirm that intracellular and extracellular A11-reactive species are present in situ in sCJD cases and GSS, and that immunoreactivity for A11 and Prp(Sc) overlaps. We argue that the A11-reactive species are indeed composed of oligomeric Prp(Sc), and suggest that the toxic effects of Prp(Sc) oligomers could be related to the generic oligomeric conformation recognized by A11.

Peritumoral brain edema in angiomatous supratentorial meningiomas: an investigation of the vascular endothelial growth factor A pathway.

The aim of this work was to study the vascular endothelial growth factor A (VEGF-A) pathway and peritumoral brain edema (PTBE) through comparison of non-angiomatous and angiomatous meningiomas. Meningiomas are common intracranial tumors, which often have PTBE. VEGF-A is an integral part of PTBE formation and angiogenesis, and the capillary-rich angiomatous meningiomas are known for their PTBE. The VEGF-A receptor VEGFR-2 is responsible for the angiogenic effect of VEGF-A on endothelial cells, which is enhanced by the co-receptor neuropilin-1. Forty non-angiomatous, 22 angiomatous meningiomas, and 10 control tissue samples were collected for the study. Magnetic resonance images were available for 40 non-angiomatous and 10 angiomatous meningiomas. Tissue sections were immunostained for CD34, MIB-1, estrogen- and progesterone receptors. ELISA, chemiluminescence, and RT-qPCR were used for VEGF-A, VEGFR-2, and neuropilin-1 protein and mRNA quantification. Angiomatous meningiomas had larger PTBE (695 vs 218 cm(3) , p = 0.0045) and longer capillary length (3614 vs 605 mm/mm(3) , p < 0.0001). VEGF-A mRNA, neuropilin-1 mRNA, and VEGFR-2 protein levels were higher in angiomatous meningiomas independently of the capillary length (p < 0.05). Neuropilin-1 protein levels were lower in angiomatous meningiomas (p < 0.0001). The VEGF-A pathway and tumor capillary length may be essential for PTBE-formation in meningiomas. Further investigations of this pathway could lead to earlier therapy and targeted pharmacological treatment options.

Vascular endothelial growth factor A protein level and gene expression in intracranial meningiomas with brain edema.

Meningiomas are the second most common primary intracranial tumors in adults. Although meningiomas are mostly benign, more than 50% of patients with meningioma develop peritumoral brain edema (PTBE), which may be fatal because of increased intracranial pressure. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen and angiogen. VEGF-A protein, which is identical to vascular permeability factor, is a regulator of angiogenesis. In this study, 101 patients with meningiomas, and possible co-factors to PTBE, such as meningioma subtypes and tumor location, were examined. Forty-three patients had primary, solitary, supratentorial meningiomas with PTBE. In these, correlations in PTBE, edema index, VEGF-A protein, VEGF gene expression, capillary length, and tumor water content were investigated. DNA-branched hybridization was used for measuring VEGF gene expression in tissue homogenates prepared from frozen tissue samples. The method for VEGF-A analysis resembled an ELISA assay, but was based on chemiluminescence. The edema index was positively correlated to VEGF-A protein (p = 0.014) and VEGF gene expression (p < 0.05). The capillary length in the meningiomas was positively correlated to the PTBE (p = 0.038). If VEGF is responsible for the formation of PTBE, the edema may be treated with the anti-VEGF drug Bevacizumab (Avastin), which has been shown to reduce PTBE in patients with glioblastoma multiforme.

Common variants of the ACE gene and aneurysmal subarachnoid hemorrhage in a Danish population: a case-control study.

OBJECTIVE: The intron 16 insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene has been associated with rupture of intracranial aneurysms, but the effect of haplotypes within ACE has not been studied. This study investigated whether ACE haplotypes including the I/D polymorphism are associated with aneurysmal subarachnoid hemorrhage. METHODS: The hypothesis was tested with a case-control design in 176 patients with aneurysmal subarachnoid hemorrhage and with 498 hospital controls. Through the pairwise tagging principle, single nucleotide polymorphisms (rs4291 A/T, rs4295 C/G, rs4305 C/T, rs4311 C/T, rs4331 T/C, rs4343 C/T) in the ACE gene were genotyped along with the I/D polymorphism. Haplotypes were estimated using the PHASE software. RESULTS: Fifty-five haplotypes were identified with 3 of these having a frequency above 5%: ACCCCIT (41.6±0.4%), TGTTTDC (32.1±0.5%), and ACCTTDC (9.5±0.2%). No significant difference in distribution of alleles, genotypes, haplotypes, or haplotype pairs between the 2 populations was found. Specifically, we could not reproduce previously reported associations between the ACE I genotype and intracranial aneurysms. When subdivided into groups of aneurysm location, we found a trend toward an association between homozygotes of the ACCCCIT haplotype and middle cerebral artery aneurysms, odds ratio=2.9 (1.0 to 7.6), which however proved insignificant (P=0.22) after correction for multiple testing. CONCLUSION: In this Danish population, ACE haplotypes and the I/D polymorphism did not contribute significantly to the overall risk of intracranial aneurysm rupture. Larger studies are needed to delineate the association between ACE polymorphism and ruptured middle cerebral artery aneurysms.

Nosocomial transmission of sporadic Creutzfeldt-Jakob disease: results from a risk-based assessment of surgical interventions.

OBJECTIVES: Evidence of surgical transmission of sporadic Creutzfeldt-Jakob disease (sCJD) remains debatable in part due to misclassification of exposure levels. In a registry-based case-control study, the authors applied a risk-based classification of surgical interventions to determine the association between a history of surgery and sCJD. DESIGN: Case-control study, allowing for detailed analysis according to time since exposure. SETTING: National populations of Denmark and Sweden. PARTICIPANTS: From national registries of Denmark and Sweden, the authors included 167 definite and probable sCJD cases with onset during the period 1987-2003, 835 age-, sex- and residence-matched controls and 2224 unmatched. Surgical procedures were categorised by anatomical structure and presumed risk of transmission level. The authors used logistic regression to determine the odds ratio (OR) for sCJD by surgical interventions in specified time-windows before disease-onset. RESULTS: From comparisons with matched controls, procedures involving retina and optic nerve were associated with an increased risk at a latency of ≥1 year OR (95% CI) 5.53 (1.08 to 28.0). At latencies of 10 to 19 years, interventions on peripheral nerves 4.41 (1.17 to 16.6) and skeletal muscle 1.58 (1.01 to 2.48) were directly associated. Interventions on blood vessels 4.54 (1.01 to 20.0), peritoneum 2.38 (1.14 to 4.96) and skeletal muscle 2.04 (1.06 to 3.92), interventions conducted by vaginal approach 2.26 (1.14 to 4.47) and a pooled category of lower-risk procedures 2.81 (1.62 to 4.88) had an increased risk after ≥20 years. Similar results were found when comparing with unmatched controls. INTERPRETATION: This observation is in concordance with animal models of prion neuroinvasion and is likely to represent a causal relation of surgery with a non-negligible proportion of sCJD cases.

Demyelination versus remyelination in progressive multiple sclerosis.

The causes of incomplete remyelination in progressive multiple sclerosis are unknown, as are the pathological correlates of the different clinical characteristics of patients with primary and secondary progressive disease. We analysed brains and spinal cords from 51 patients with progressive multiple sclerosis by planimetry. Thirteen patients with primary progressive disease were compared with 34 with secondary progressive disease. In patients with secondary progressive multiple sclerosis, we found larger brain plaques, more demyelination in total and higher brain loads of active demyelination compared with patients with primary progressive disease. In addition, the brain density of plaques with high-grade inflammation and active demyelination was highest in secondary progressive multiple sclerosis and remained ~18% higher than in primary progressive multiple sclerosis after adjustments for other plaque types and plaque number (P<0.05). Conversely, the proportion of remyelinated shadow plaques (P<0.05) and the overall remyelination capacity (P<0.01) per brain were higher in primary, compared with secondary, progressive multiple sclerosis. By contrast, there were no group differences in the brain load or frequency of low-grade inflammatory plaques with slowly expanding demyelination. Spinal cord lesion loads and remyelination capacity were also comparable in the two patient groups. Remyelinated areas were more vulnerable than the normal-appearing white matter to new demyelination, including active demyelination in secondary progressive multiple sclerosis. 'Recurrent' slowly expanding demyelination, affecting remyelinated areas, and the load of slowly expanding demyelination correlated with incomplete remyelination in both groups. In turn, incomplete remyelination in the spinal cord correlated with higher disease-related disability (determined retrospectively; r = -0.53; P<0.05 for remyelination capacity versus disease severity). By contrast, such a correlation was not observed in the brain. We propose that regulatory and reparative properties could protect the white matter of the brain in patients with primary progressive multiple sclerosis. These patients may, thereby, be spared symptoms until the spinal cord is affected. By contrast, recurrent active demyelination of repaired myelin could explain why similar symptoms often develop in consecutive relapses in relapsing-remitting/secondary progressive multiple sclerosis. Our data also indicate that slowly expanding demyelination may irreparably destroy normal and repaired myelin, supporting the concept of slowly expanding demyelination as an important pathological correlate of clinical progression.

Spatiotemporal distribution of PAX6 and MEIS2 expression and total cell numbers in the ganglionic eminence in the early developing human forebrain.

The development of the human neocortex is a complex and highly regulated process involving a time-related expression of many transcription factors including the homeobox genes Pax6 and Meis2. During early development, Pax6 is expressed in nuclei of radial glia cells in the neocortical proliferative zones and controls the differentiation and neurogenetic fate of these cells in the dorsal telencephalon in rodents. Animal studies on the Meis2 gene have revealed expression in the developing telencephalon and Meis2 is known to regulate the expression of Pax6 in the eye and pancreas. Because of this functional relation between Pax6 and Meis2, we studied the spatial and temporal expression of PAX6, and MEIS2 using a developmental series of human fetal brains at 7-19 postconceptional weeks with emphasis on the forebrain to investigate whether the two genes are expressed in the same regions and zones in the same time window. We demonstrate by in situ hybridization and immunohistochemistry that the two homeobox genes are expressed during early fetal brain development in humans. PAX6 mRNA and protein were located in the proliferative zones of the neocortex and in single cells in the cortical preplate at 7 fetal weeks and in the developing cortical plate from 8 or 9 to 19 fetal weeks. The expression of PAX6 expanded into the ganglionic eminence just prior to the stage at which a stereological estimation showed an exponential rise in total cell number in this area. The MEIS2 gene was also present in the proliferative zones of the human fetal neocortex and a higher expression of MEIS2 than PAX6 was observed in these areas at 9 fetal weeks. Further, MEIS2 was expressed at a very high level in the developing ganglionic eminence and at a more moderate level in the cortical plate.