Education as Risk Factor of Mild Cognitive Impairment: The Link to the Gut Microbiome.

BACKGROUND: With differences apparent in the gut microbiome in mild cognitive impairment (MCI) and dementia, and risk factors of dementia linked to alterations of the gut microbiome, the question remains if gut microbiome characteristics may mediate associations of education with MCI. OBJECTIVES: We sought to examine potential mediation of the association of education and MCI by gut microbiome diversity or composition. DESIGN: Cross-sectional study. SETTING: Luxembourg, the Greater Region (surrounding areas in Belgium, France, Germany). PARTICIPANTS: Control participants of the Luxembourg Parkinson's Study. MEASUREMENTS: Gut microbiome composition, ascertained with 16S rRNA gene amplicon sequencing. Differential abundance, assessed across education groups (0-10, 11-16, 16+ years of education). Alpha diversity (Chao1, Shannon and inverse Simpson indices). Mediation analysis with effect decomposition was conducted with education as exposure, MCI as outcome and gut microbiome metrics as mediators. RESULTS: After exclusion of participants below 50, or with missing data, n=258 participants (n=58 MCI) were included (M [SD] Age=64.6 [8.3] years). Higher education (16+ years) was associated with MCI (Odds ratio natural direct effect=0.35 [95% CI 0.15-0.81]. Streptococcus and Lachnospiraceae-UCG-001 genera were more abundant in higher education. CONCLUSIONS: Education is associated with gut microbiome composition and MCI risk without clear evidence for mediation. However, our results suggest signatures of the gut microbiome that have been identified previously in AD and MCI to be reflected in lower education and suggest education as important covariate in microbiome studies.

Oral administration of transgenic barley expressing a Culicoides allergen induces specific antibody response.

BACKGROUND: Insect bite hypersensitivity is an immunoglobulin (Ig)E-mediated dermatitis of horses initiated by bites of midges of the genus Culicoides. Culicoides spp. are not indigenous to Iceland and the prevalence of insect bite hypersensitivity is much higher in horses born in Iceland and exported as compared to Icelandic horses born in a Culicoides rich environment. Immunotherapy is therefore needed. OBJECTIVES: The aim of the study was to express an allergen from Culicoides in barley grain and investigate whether an immune response could be obtained in healthy Icelandic horses by oral treatment with transgenic barley expressing the allergen. STUDY DESIGN: In vivo experiment. METHODS: The allergen was expressed in barley grain with the Orfeus technique. A device was developed to treat horses orally with barley flour. Four Icelandic horses were treated with transgenic barley and 3 with control barley, in total 500 g in 7 feedings. Serum and saliva samples were collected for measuring specific antibodies. RESULTS: The allergen Cul n 2, a hyaluronidase originating from the salivary gland of Culicoides nubeculosus, was expressed in barley. Horses treated with the transgenic barley mounted a Cul n 2 specific IgG1 and IgG4/7 response in serum and saliva. The serum response was significantly different between the transgenic and control barley treated horses for both subclasses and the saliva response for IgG1. The induced serum antibodies bound to the corresponding allergen from Culicoides obsoletus, rCul o 2 and were able to partially block binding of Cul n 2 as well as Cul o 2 specific IgE from insect bite hypersensitivity affected horses. MAIN LIMITATIONS: Small number of horses. CONCLUSION: This study shows that specific antibody response can be induced in horses not exposed to Culicoides, using oral treatment with transgenic barley expressing an allergen. Further studies will determine whether this approach is a useful alternative for prevention and treatment of equine insect bite hypersensitivity.

Effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile and inflammation markers in metabolic syndrome -- a randomized study (SYSDIET).

BACKGROUND: Different healthy food patterns may modify cardiometabolic risk. We investigated the effects of an isocaloric healthy Nordic diet on insulin sensitivity, lipid profile, blood pressure and inflammatory markers in people with metabolic syndrome. METHODS: We conducted a randomized dietary study lasting for 18-24 weeks in individuals with features of metabolic syndrome (mean age 55 years, BMI 31.6 kg m(-2) , 67% women). Altogether 309 individuals were screened, 200 started the intervention after 4-week run-in period, and 96 (proportion of dropouts 7.9%) and 70 individuals (dropouts 27%) completed the study, in the Healthy diet and Control diet groups, respectively. Healthy diet included whole-grain products, berries, fruits and vegetables, rapeseed oil, three fish meals per week and low-fat dairy products. An average Nordic diet served as a Control diet. Compliance was monitored by repeated 4-day food diaries and fatty acid composition of serum phospholipids. RESULTS: Body weight remained stable, and no significant changes were observed in insulin sensitivity or blood pressure. Significant changes between the groups were found in non-HDL cholesterol (-0.18, mmol L(-1) 95% CI -0.35; -0.01, P = 0.04), LDL to HDL cholesterol (-0.15, -0.28; -0.00, P = 0.046) and apolipoprotein B to apolipoprotein A1 ratios (-0.04, -0.07; -0.00, P = 0.025) favouring the Healthy diet. IL-1 Ra increased during the Control diet (difference -84, -133; -37 ng L(-1) , P = 0.00053). Intakes of saturated fats (E%, beta estimate 4.28, 0.02; 8.53, P = 0.049) and magnesium (mg, -0.23, -0.41; -0.05, P = 0.012) were associated with IL-1 Ra. CONCLUSIONS: Healthy Nordic diet improved lipid profile and had a beneficial effect on low-grade inflammation.

The biomechanical behaviour of the hyalinized periodontal ligament in dogs during experimental orthodontic tooth movement.

During orthodontic tooth movement, the mechanical behaviour of the extracellular matrix of the periodontal ligament (PDL) determines the cellular processes involved in turnover of the PDL and alveolar bone. This mechanical behaviour is the basis for finite element (FE) models and FE analyses. Five young adult male beagle dogs were used to test the null hypothesis that the mechanical behaviour of the PDL is identical in normal and hyalinized PDL. Therefore, tooth transposition was measured after standardized force application by super-elastic nickel titanium (NiTi) coil springs, exerting a constant force of 100 cN for 5 hours in both conditions. A rapid transposition during the first few seconds was found. However, it was significantly less for hyalinized than for non-hyalinized PDL. Subsequently, a short-lived creep movement was found for hyalinized PDL, while creep persisted at the non-hyalinized sides (analysis of variance and Tukey's multiple comparisons post hoc tests). The results showed substantial biomechanical differences between hyalinized and non-hyalinized PDL at different time points (Mann-Whitney). This indicates that FE models in the study of long-term orthodontic tooth movement, which are based solely on the characteristics of normal PDL should be reconsidered.

Individual patient meta-analysis of exercise training effects on systemic brain natriuretic peptide expression in heart failure.

BACKGROUND: Brain natriuretic peptide (BNP) predicts exercise performance and exercise training may modulate BNP and its N-terminal portion (NT-pro-BNP), we therefore conducted an individual patient analysis of exercise training effects on BNP and NT-pro-BNP. AIMS: To use an individual patient meta-analysis to relate changes in BNP, NT-pro-BNP, and peak VO(2); to link these changes to volume parameters of exercise training programmes (intensity etc.); and to identify patient characteristics likely to lead to greater improvements in BNP, NT-pro-BNP, and peak VO(2). DESIGN: Individual patient meta-analysis. METHODS: A systematic search was conducted of Medline (Ovid), Embase.com, Cochrane Central Register of Controlled Trials, and CINAHL (until July 2008) to identify randomized controlled trials of aerobic and/or resistance exercise training in systolic heart failure patients measuring BNP and/or NT-pro-BNP. Primary outcome measures were change in BNP, NT-pro-BNP, and peak VO2. Subanalyses were conducted to identify (1) patient groups that benefit most and (2) exercise programme parameters enhancing favourable changes in primary outcome measures. RESULTS: Ten randomized controlled studies measuring BNP or NT-pro-BNP met eligibility criteria, authors provided individual patient data for 565 patients (313 exercise and 252 controls). Exercise training had favourable effects on BNP (-28.3%, p < 0.0001), NT-pro-BNP (-37.4%, p = < 0.0001), and peak VO(2) (17.8%, p < 0.0001). The analysis showed a significant change in primary outcome measures; moreover, change in BNP (r = -0.31, p < 0.0001) and NT-pro-BNP (r = -0.22, p < 0.0001) were correlated with peak VO(2) change. CONCLUSION: Exercise training has favourable effects on BNP, NT-pro-BNP, and peak VO(2) in heart failure patients and BNP/NT-pro-BNP changes were correlated with peak VO(2) changes.

Prediction of pH-dependent aqueous solubility of Histone Deacetylase (HDAC) inhibitors.

Recently we developed a model for prediction of pH-dependent aqueous solubility of drugs and drug like molecules. In the present work, the model was applied on a series of novel Histone Deacetylases (HDAC) inhibitors discovered at TopoTarget. The applicability of our model was evaluated on the series of HDAC inhibitors by use of Self-Organizing Maps (SOM) and 2D-projection of the HDAC inhibitors on the chemical space of the training data set of the artificial neural network (ANN) module. The model was refined for the particular chemical space of interest, which led to two modifications in the training data set of the ANN. The performance of the original and the two modified versions of the model were evaluated against the commercial software from Simulations-plus and pH-dependent solubility measurements for representative compounds of the series. The results of the evaluation indicate that one can develop models that are more accurate in predicting differences in the solubility of structurally very similar compounds than models that have been trained on structurally unbiased, diverse data sets. Such 'tailor-made' models have the potential to become trustworthy enough to replace time-consuming and expensive medium- and high-throughput solubility experiments by providing results of similar or even better quality.

The long pentraxin PTX-3 in prevalent hemodialysis patients: associations with comorbidities and mortality.

BACKGROUND: Pentraxin (PTX)-3, a new candidate marker for inflammation is expressed in a variety of cell types. Recently, we have shown that increase in PTX-3 level is associated with clinical outcome in incident CKD stage 5 patients at start of renal replacement therapy. However, no data are available on PTX-3 and its relationship with clinical outcome in prevalent dialysis patients. METHODS: We analyzed plasma PTX-3 concentrations in relation to comorbidities (Davies score), protein-energy wasting (PEW) and inflammation markers in 200 prevalent hemodialysis (HD) patients, aged 64 +/- 14 years, who had been on HD treatment for a median period of 36 months. Survival (42 months) was analyzed in relation to PTX-3 levels (high PTX-3 tertile vs. low two tertiles). RESULTS: Plasma PTX-3 correlated positively with C-reactive protein and interleukin-6, and negatively with s-albumin and fetuin-A. Patients with cardiovascular disease (CVD) and PEW had higher levels of PTX-3 than their counterparts and PTX-3 was associated with comorbidity score. In multiple logistic regression analysis, the high comorbidity score and PEW were the significant predictive variables of high PTX-3. In unadjusted analysis high PTX-3 was significantly associated with all-cause mortality. After adjustment for sex, age, dialysis vintage, comorbidity score, PEW and CRP using the multivariate Cox regression analysis, death rate was still significantly higher in patients with high PTX-3 (HR 1.7; CI 1.1-2.7, P = 0.03). CONCLUSION: Markedly increased levels of PTX-3 were found in HD patients with signs of CVD and PEW. In addition, the concentration of PTX-3 was associated with inflammation markers and comorbidity score. Our data also shows that high PTX-3 level was independently associated with all-cause mortality.

Biomechanical behaviour of the periodontal ligament of the beagle dog during the first 5 hours of orthodontic force application.

The aim of this study was to describe the mechanical behaviour of the periodontal ligament (PDL) in response to loading with different forces for a period of 5 hours. Seven young adult male beagle dogs (age 1.0-1.5 years) were used. After extractions and placement of implants, custom-made appliances on both sides of the mandible were used to measure the displacement of the second premolars. Tooth displacement was measured during 5 hours of force application. Each dog underwent two measurement sessions. One premolar was moved with a force of 100 cN in the first session and with 50 cN in the second. The contralateral premolar was moved with forces of 100 and 300 cN, respectively. Time-displacement curves showed a rapid instantaneous response lasting only a few seconds followed by a slowly decreasing creep displacement. The instantaneous response demonstrated a large individual variability, caused by both a dog and a force effect. Differences in tooth and PDL anatomy and in the orientation of the periodontal fibres are probably important in this respect. The individual variability faded after the first seconds of tooth displacement, when the viscoelastic properties of the periodontal fibres became more pronounced. The force effect was non-linear for the first minute. Higher forces did not lead to proportionally larger displacements. The non-linearity decreased in the second response. The PDL is a complex material that might be considered as a non-linear fibre-reinforced poroviscoelastic material.

[Fetal alcohol syndrome and alcohol-related neuro-developmental disorder. A review.].

Prenatal alcohol exposure can have devastating consequences for the unborn child. The physical malformations and growth retardation characteristic of the fetal alcohol syndrome (FAS) only represent the tip of the teratological iceberg. The functional impairments that are not obvious to the eye have the most detrimental consequences for the individual. The cognitive and behavioral problems seen in alcoholexposed children are caused by alterations in brain function and/or structure. The extent of damage to the brain is time and dose related. Fetal alcohol syndrome and alcohol-related neurodevelopmental disorder (ARND) have been estimated to affect as many as 9.1 children per 1,000 according to a prospective study in Seattle, USA. Long-term outcome reveals an excess of social and mental problems. The incidence of FAS and ARND in Icelandic children is unknown. Various research outcomes and implications for therapy are discussed.

A study of the association of HLA DR, DQ, and complement C4 alleles with systemic lupus erythematosus in Iceland.

OBJECTIVE: To perform an exploratory analysis of the relative contribution of single MHC genes to the pathogenesis of systemic lupus erythematosus (SLE) in a homogenous white population. METHODS: MHC class II alleles and C4 allotypes were determined in 64 SLE patients and in ethnically matched controls. HLA-DR and DQ typing was performed by polymerase chain reaction amplification with sequence specific primers. C4 allotypes were determined by agarose gel electrophoresis. RESULTS: The frequency of C4A*Q0 was significantly higher in patients than in controls (46.9% v 25.3%, p = 0.002). HLA-DRB1, DQA1, and DQB1 alleles in the whole group of SLE patients were not significantly different from those of controls. On the other hand increase in DRB1*03 was observed in the group of patients with C4A*Q0, as compared with patients with other C4A allotypes (p = 0.047). There was no significant correlation between severe and mild disease, as judged by the SLEDAI, and HLADR, DQ alleles and comparing the patients with C4A*Q0 with those with other C4A allotypes there was no significant difference regarding clinical manifestations. CONCLUSION: The results are consistent with the argument that C4A deficiency contributes independently to susceptibility and the pathogenesis of SLE. C4A*Q0 in SLE patients in Iceland shows weaker linkage disequilibrium with DR3 genes than reported in most other white populations and emphasises the role of ethnicity.

Inhibitory effects of baeomycesic acid from the lichen Thamnolia subuliformis on 5-lipoxygenase in vitro.

Baeomycesic acid (1), a ß-orcinol depside isolated from the lichen Thamnolia subuliformis (Ehrh.) W. Culb. was tested for in vitro inhibitory effects on arachidonate metabolism. Results showed that baeomycesic acid has potent dose-dependent inhibitory effects on 5-lipoxygenase isolated from porcine leucocytes, with an IC(50) value of 8.3 µM. Structure-activity relationships are discussed in comparison to other phenolic lichen constituents. Baeomycesic was inactive when tested for in vitro inhibitory effects against cyclooxygenase isolated from sheep seminal vesicle microsomes.

Progressive dementia and leucoencephalopathy as the initial presentation of late onset hereditary cystatin-C amyloidosis. Clinicopathological presentation of two cases.

Hereditary Cystatin-C Amyloidosis (HCCA) is a genetic disorder in Icelandic families in which a defective cystatin-C amyloid protein is deposited in the walls of small and middle sized arteries. Cerebral vessels are most affected, resulting in recurrent cerebral hemorrhages and infarctions, usually with onset of clinical symptoms in the twenties or thirties and a rapidly deteriorating clinical course. The disease can be diagnosed by a skin biopsy in symptomatic patients. We report two patients (father and daughter) who did not have a known family history of the disorder and presented late in life with a progressive dementia, associated with cerebral hemorrhages in the younger patient. Cerebral MRI and CT scans of this patient showed extensive leukoencephalopathic changes. Brain tissue samples from both patients showed immunohistochemical reaction to cystatin-C in small and medium-sized cerebral arteries and extensive cortical and white matter microinfarctions. The amyloid changes were less severe in the older patient and a colocation of beta-amyloid protein and cystatin-C was observed in addition to neurofibrillary tangles and senile plaques. Subcortical and cortical infarctions were also observed. HCCA may present late in life with progressive dementia as the only clinical manifestation, reflecting a multi-infarct syndrome secondary to the amyloidosis. A coexpression of cystatin-C and beta protein may occur as in other cerebral amyloid disorders, probably as age-specific changes.

A study of the major histocompatibility complex in a Caucasian family with multiple cases of systemic lupus erythematosus: association with the C4AQ0 phenotype.

OBJECTIVE: In an epidemiological survey of systemic lupus erythematosus (SLE) in Iceland several families with multiple cases were identified. In one family, 35 individuals (family members and spouses) in 3 generations were studied clinically, tested for autoantibody formation, and typed for HLA and toxicity complement phenotypes. METHODS: Typing for HLA-A, B, C, DR, and DQ was performed by microlymphocytotoxic assay. In selected samples HLA-DR typing by polymerase chain reaction amplification with sequence specific primers was performed. C4 allotypes were defined by agarose gel protein electrophoresis followed by immunofixation with goat antisera. RESULTS: Five family members fulfilled 4 or more criteria for SLE. Additionally, 5 family members had clinical manifestations or positive serology but did not fulfill 4 ARA criteria. The mean age at onset of symptoms was 22 yrs (8-40). Other autoimmune diseases were not documented in family members. C4A null seemed to be highly associated with disease in this family. All except one patient with SLE and all those with clinical manifestations and positive serology had C4A null in the homozygous or heterozygous form. The individual with SLE and not carrying C4A null had both HLA haplotypes identical. It is noteworthy that there were 5 different C4A null bearing haplotypes involved, of which 3 originated from the spouses. CONCLUSION: Our results are consistent with the argument that C4A deficiency plays a role in the pathogenesis of SLE. There is, however, the possibility of an unidentified environmental or another genetic factor being involved.

[Mild haemophilia A in Iceland.].

A family survey of mild hemophilia A has been carried out during the last 25 years. Presently these families contain 27 living affected males or approximately twice the number of males with severe form of hemophilia A in Iceland. The aim of the study was to define the phenotype in three families with mild haemophilia A and to determine RFLP (Restriction Fragment Length Polymorphism) polymorphisms, which could support a hypothesis of a common progenitor of the families. Family survey was made and index cases were identified in and outside hospitals and a survey for symptoms and signs of bleeding in family members and sampling for coagulation and RFLP studies were mostly carried out in the field. Family members with and without symptoms of bleeding were selected for investigation and normal spouses and unrelated individuals were investigated for control. Bleeding time, factor VIII activity, quantification of factor VIII Ag, von Wil-lebrand factor Ag and vWF ristocetin assay. Typing of RFLP polymorphisms for genetic homogeneity. Bleeding manifestations are present in both sexes in the three families although more frequent and more severe in the males. Prolonged bleeding time in 6 of 7 affected members in one of the families and subnormal levels in von Willebrand related assays point to an additional abnormality which has not been explained. The level of factor VIII activity is between 10-20% in most affected males whereas 35-60% is found approximately in 2/3 of females carriers and in 1/3 of them factor VIII activity is within the normal range. Major bleeding episodes in family members are associated with accidents, surgical procedures menorrhagia and in some cases provoked by diseases such as intestinal ulceration, kidney stones and abnormalities of vasculature. RFLP polymorphisms were detected, which are common to the families and they support hypothesis of a common progenitor. The genetic studies show relatively high prevalence of this type of mild haemophilia A, which seems to have been present for at least 6-8 generations in Iceland. It is suggested that screening for this mild haemophilia A gene by molecular genetic method would be of clinical value now, when it's mutation has been detected. Transmission of mild haemophilia A through 6-9 generations is demonstrated by the study. Founder effect is confirmed by studies of RFLP polymorphisms. The mild haemophilia A type described is the most prevalent of haemophilia A types in Iceland (population 265,000, 1993).

Mild haemophilia A in Iceland: clinical genetic studies of three families with the same mutation.

OBJECTIVES: The aim of the study was to define the phenotype in three families with mild haemophilia A and to determine restriction fragment length polymorphisms (RFLP), which could support a hypothesis of a common progenitor of the families. DESIGN: Family survey. SETTING: Index cases were identified in and outside hospital and a family survey for symptoms and signs of bleeding in family members and sampling for coagulation and RFLP studies were mostly carried out in the field. SUBJECT: Family members with and without symptoms of bleeding were selected for investigation and normal spouses and unrelated individuals were investigated for control. INTERVENTIONS: Medical advice regarding affected family members were given to the families and their physicians. MAIN OUTCOME MEASURES: Bleeding time, factor VIII activity, quantification of factor VIII:Ag, von Willebrand factor (vWF) Ag and vWF ristocetin assay. Typing of RFLP polymorphisms for genetic homogeneity. RESULTS: Bleeding manifestations are present in both sexes in the three families although more frequent and more severe in the males. The level of factor VIII activity is between 10 and 20% in most affected males whereas 35-60% is found approximately in 2/3 of female carriers and in 1/3 of them factor VIII activity is within the normal range. It is suggested that screening for this mild haemophilia A gene by a molecular genetic method would be of clinical value now, its mutation having been detected. CONCLUSIONS: Transmission of mild haemophilia A through six to seven generations is demonstrated by the study. The mild haemophilia A type described is the most prevalent of haemophilia A types in Iceland (population 260,000, 1992). The founder effect was confirmed by studies of RFLP polymorphisms.

Molecular diagnosis of hereditary cystatin C amyloid angiopathy.

Hereditary cystatin C amyloid angiopathy (HCCAA) is an autosomal dominant disorder characterized by the deposition of amyloid in most investigated tissues. The main component of the amyloid deposits is a variant of the cysteine proteinase inhibitor cystatin C, and the most serious consequence of the disease is that amyloid deposition in the cerebral arteries leads to a massive brain hemorrhage and death before 40 years of age. HCCAA has been shown to be caused by a T-->A point mutation in the codon for leucine at position 68 in exon 2 of the cystatin C gene, which results in a leucine-->glutamine amino acid substitution in the cystatin C molecule. Since the HCCAA-causing mutation abolishes an AluI restriction site in the cystatin C gene, analysis of this AluI restriction fragment-length polymorphism (RFLP) enables simple and accurate molecular diagnosis of HCCAA. One hundred ninety-one individuals have now been screened for the HCCAA causing mutation, including a fetus for prenatal diagnosis. Thirty-six individuals belonging to nine Icelandic families have been found to have the mutation and it is highly probable that these families descend from a common ancestor.

Hereditary cystatin C amyloid angiopathy: identification of the disease-causing mutation and specific diagnosis by polymerase chain reaction based analysis.

Hereditary cystatin C amyloid angiopathy (HCCAA) is a dominantly inherited disease characterized by amyloidosis, dementia and fatal cerebral hemorrhage of young adults. A method for rapid and simple diagnosis of HCCAA is described. It is based upon oligonucleotide-directed enzymatic amplification of a 275-bp genomic DNA segment containing exon 2 of the cystatin C gene from a blood sample, followed by digestion of the amplification product with AluI. Loss of an AluI recognition site in the amplified DNA segment from HCCAA patients results in a deviating band-pattern at agarose gel electrophoresis, compared with that obtained from normal subjects or unaffected HCCAA family members. In a population of 9 patients with manifest HCCAA, 14 patients with other causes of brain hemorrhage and 16 healthy individuals, the diagnostic procedure displayed a sensitivity and specificity for HCCAA of 100%. Amplified DNA segments from 4 HCCAA patients of four different families were analyzed by nucleotide sequencing; the HCCAA-causing mutation in all families was found to be a single T----A substitution in the codon for amino acid residue 68 of cystatin C.