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Biomedical subjects

J Partanen

Publications and source records attributed to J Partanen.

At least 91 records · Page 5Linked to original sources

Association of HLA B27 with benign clinical course of nephropathia epidemica caused by Puumala hantavirus.

Both the severe course of nephropathia epidemica (NE) caused by Puumala hantavirus, and the fast progression of human immunodeficiency virus (HIV) disease, are associated with the HLA B8 DRB1*0301 haplotype. As HLA B27, on the contrary, is associated with the slow progression of HIV disease, we wanted to test whether the same is true for NE. Only six (8%) NE patients, half the figure expected, had the HLA B27 allele in 74 randomly selected hospital-treated patients. All six had a benign overall clinical course of NE; none had any severe complications, the severity of renal failure was also mild, and the treatment time at the hospital was half that needed for HLA B27- patients (P = 0.004). Patients who were HLA B27 had maximal blood leucocyte count > 10.000 x 10(9)/L (P = 0.020) more often, probably reflecting differences in immune response. Thus, similar HLA associations can be found in both HIV infection and NE caused by Puumala virus.

Adult↗

Celiac disease risk in the USA: high prevalence of antiendomysium antibodies in healthy blood donors.

BACKGROUND: Recent epidemiologic studies in Europe using antigliadin (AGA) and anti-endomysium antibodies (AEA) for initial screening have shown that the overall prevalence of celiac disease (CD) is about 1:300. There are no comparable scientific data for the USA, where CD is considered rare. The main aim of this study was to determine the prevalence of increased AEA in healthy blood donors in the USA. METHODS: Sera from 2000 healthy blood donors were screened for IgG AGA and IgA AGA with an enzyme-linked immunosorbent assay test. All those with increased AGA levels, those with intermediate levels, and random samples with low levels were tested for AEA, using both monkey esophagus (ME) and human umbilical cord (HUC) cryosections as substrates. RESULTS: The mean age of the blood donors was 39 years, with 52% being men, 85.2% being Caucasian, 11.8% African-American, 1.5% Asian, and 1.5% Hispanic. Eight healthy blood donors had positive AEA tests on both monkey esophagus and human umbilical cord. Among the eight subjects with increased AEA levels seven were Caucasian and one was African-American. All the four examined AEA-positive donors carried the known susceptibility alleles for CD. CONCLUSIONS: The prevalence of increased AEA levels in healthy blood donors in the USA is 1:250 (8:2000). This is similar to that reported in countries in Europe, where subsequent small-intestinal biopsies have confirmed CD in all those with AEA positivity. On the basis of a high positive predictive value of the AEA antibody test, it is likely that the eight blood donors identified in this study have CD. These data suggest that CD is not rare in the USA and that there is need for a large-scale epidemiologic study to determine the precise prevalence of the disease in the USA.

Adolescent↗

High-producer allele of tumour necrosis factor-alpha is part of the susceptibility MHC haplotype in severe puumala virus-induced nephropathia epidemica.

The biallelic polymorphisms in the tumour necrosis factor-alpha (TNF-alpha) gene promoter region were studied in patients with nephropathia epidemica (NE). The rarer TNF2 allele, associated with a high TNF-alpha producer phenotype, was more frequently found in hospitalized NE patients (42%) than in healthy controls (15%; p=0.0064). The putative role of TNF2 as an independent risk factor for NE is discussed.

Alleles↗

Amlodipine in patients with stable angina pectoris treated with beta-blockers. Double-blind comparison with placebo.

In order to assess additional anti-ischaemic effects of amlodipine (AML) on coronary artery disease (CAD) treated with beta-blockers, 32 patients with CAD, verified on angiograms, and stable angina were randomized to receive 5 mg/day of AML or placebo, increasing to 10 mg/day after 2 weeks. Baseline recording of 24-h ambulatory ECG and blood pressure, echocardiography and bicycle exercise test was repeated after treatment for 2 weeks and for 6 weeks. Reduction of ambulatory ischaemia was not significantly greater with AML than with placebo. In exercise tests the time to 0.1 mV ST segment depression and the total exercise time remained unaltered. Blood pressure was reduced by 10 mg AML. The total variability and the very low frequency component of heart rate were reduced after both doses. The clinical significance of the possible unfavourable change in autonomic modulation of the heart in CAD patients is not known.

Adrenergic beta-Antagonists↗

Assignment of the tibial muscular dystrophy locus to chromosome 2q31.

Tibial muscular dystrophy (TMD) is a rare autosomal dominant distal myopathy with late adult onset. The phenotype is relatively mild: muscle weakness manifests in the patient's early 40s and remains confined to the tibial anterior muscles. Histopathological changes in muscle are compatible with muscular dystrophy, with the exception that rimmed vacuoles are a rather common finding. We performed a genomewide scan, with 279 highly polymorphic Cooperative Human Linkage Center microsatellite markers, on 11 affected individuals of one Finnish TMD family. The only evidence for linkage emerged from markers in a 43-cM region on chromosome 2q. In further linkage analyses, which included three other Finnish TMD families and which used a denser set of markers, a maximum two-point LOD score of 10.14 (recombination fraction of .05) was obtained with marker D2S364. Multipoint likelihood calculations, combined with the haplotype and recombination analyses, restricted the TMD locus to an approximately 1-cM critical chromosomal region without any evidence of heterogeneity. Since all the affecteds share one core haplotype, the dominance of one ancestor mutation is obvious in the Finnish TMD families. The disease locus that was found represents a novel muscular dystrophy locus, providing evidence for the involvement of one additional gene in the distal myopathy group of muscle disorders.

Adult↗

TNF microsatellite alleles a2 and b3 are not primarily associated with celiac disease in the Finnish population.

Recently, an independent association between tumor necrosis factor (TNF) gene polymorphism and celiac disease was observed in the Irish population. We tested this association in Finnish patients with celiac disease. The TNF microsatellite alleles a2 and b3 were strongly associated (Pcorr<0.0001 for both) with celiac disease when the patients were compared to the random population. However, when the comparison was made with the DQ2-matched controls, no association could be found. We therefore conclude that in Finland the TNFa2 and b3 alleles are associated with DQ2-positive haplotypes rather than celiac disease.

Alleles↗

Genetic polymorphism in human platelet glycoprotein GP Ib/IX/V complex is enriched in GP V (CD42d).

Platelet glycoproteins Ib beta (CD42c), IX (CD42a), and V (CD42d), together with GP Ib alpha (CD42b), form a receptor whose interaction with the von Willebrand factor is essential in the initial stages of haemostasis. Genetic variation in these proteins can cause alloimmunization leading to neonatal alloimmune thrombocytopenia and platelet transfusion refractoriness. Defective mutations cause a rare bleeding disorder, Bernard-Soulier syndrome. Only two antigenic polymorphisms have thus far been established in these proteins: the HPA-2 in GP Ib alpha and the rare Iy variant in GP Ib beta. Recently, we reported that only a limited degree of polymorphism can be found in the GP Ib alpha gene; the level of variation in the other components is not known. We therefore systematically screened polymorphism in the GP Ib beta, GP IX, and GP V genes in 50 unrelated Finnish blood donors. Nine polymorphic sites were found in the GP V gene, of which four changed the amino acid code and five were silent. The gene frequencies for substitutions Asp114Tyr, Met273Ile, Gly341Arg, and Leu397Arg were 1%, 1%, 2%, and 1% respectively. The five silent polymorphisms also had low frequencies, 1-4%. No polymorphism was found in the GP Ib beta gene and only one mutation was found in the 3' untranslated region of the GP IX gene. Our results indicate that genetic variation in the GP Ib/IX/V complex is mostly tolerated in the GP V protein--whose function in the complex is not clear whereas the other components have only very limited genetic polymorphism.

Blood Donors↗

Genetic susceptibility to gluten sensitive enteropathy in Irish setter dogs is not linked to the major histocompatibility complex.

Gluten sensitive enteropathy (GSE) in Irish setter dogs has been proposed as an animal model for human celiac disease (CD), in which the major histocompatibility complex (MHC) class II alleles HLA DQA1*0501 and DQB1*0201 play an important role. To investigate whether an orthologous MHC class II region is involved in canine GSE, we undertook a linkage study in two large families of gluten sensitive Irish setter dogs. A total of 44 dogs in these pedigrees were genotyped for DQA1, DQB1 and C.2202 alleles, along with 30 unrelated healthy Irish setters. No genetic linkage between the DQ or C.2002 loci and GSE was detected. In contrast to CD, susceptibility to canine GSE does not appear to be determined by variation within the MHC class II gene cluster. Therefore, canine GSE may not be an appropriate model for CD, but nevertheless remains an important disease for advancing knowledge of pathological processes in the intestine.

Alleles↗

Genetic polymorphism H131R of Fcgamma receptor type IIA (FcgammaRIIA) in a healthy Finnish population and in patients with or without platelet-associated IgG.

Patients (n=113) with histories of thrombocytopenia and with different profiles for platelet-associated IgG (PA-IgG) were subdivided according to the genetic polymorphism H131R in the Fcgamma receptor type IIA (FcgammaRIIA). PA-IgG was measured by the direct platelet immunofluorescence test (PIFT), and GP IIbIIIa and/or GP Ib-specific PA-IgG was investigated by a modified version of the direct monoclonal antibody-specific immobilization of platelet antigens (MAIPA) assay. As a control, the distribution of FcgammaRIIA polymorphism H131R was determined among 93 healthy Finnish blood donors. The frequencies for H131 and R131 were 0.56 and 0.44 (CI: 0.37-0.51), respectively, which did not differ significantly from those in other Caucasian populations. The distribution of the genotypes HH131, HR131 and RR131 in the patients and controls did not differ significantly. In the HH131 group, the PA-IgG was higher than in the RR131 group (p=0.082). Female patients with the genotype RR131 seemed to be younger than those with HH131 (p=0.065). Among the female patients, a significantly greater number were under 40 yr old in the RR131 group than in the HH131 group (p=0.0060). Within the RR131 group, the female patients were far younger than the male patients (median 29 vs. 61 yr; p=0.0021). The results point to the heterogeneity of immune thrombocytopenia, which may partly explain the poor predictive value of PA-IgG studies.

Adult↗

Dual cerebral processing of elementary auditory input in children.

We compared event-related responses (ERPs) to non-attended frequent and intermittent auditory input in school-aged children and in young adults. In adults, both inputs elicited prominent auditory N100 responses at vertex. In children, intermittent stimulation evoked vertex responses with similar latency and refractoriness, whereas frequently delivered identical tones evoked responses on average at 240 ms. Sensitization of a separate neuronal population at 260-300 ms was obvious during intermittent stimulation in children. The dual behaviour, simultaneous 'habituation' of one neuronal population response and sensitization of another, may reflect the process of redirecting the attention and setting up a neuronal model. Furthermore, results suggest that a simplistic interpretation of developmental ERPs in which shortening of latencies represents maturation is insufficient.

Acoustic Stimulation↗

Celiac patients predominantly inherit HLA-DPB1*0101 positive haplotype from HLA-DQ2 homozygous parent.

The DQA1*0501 and DQB1*0201 alleles (hereafter DQ2) confer genetic susceptibility to celiac disease (CD). Some studies have indicated that the DPB1, DMB, and TAP loci, that are located close to the DQ genes, could also together with DQ or independently confer genetic susceptibility to CD. Some others have claimed that these associations result merely from linkage disequilibrium, a hallmark of the MHC, that often makes the precise mapping of susceptibility genes difficult. To evaluate further the role of class II genes in CD, we analyzed segregation of DPB1 alleles in families with CD. In particular, we analyzed families where one of the parents was homozygous for the DQ2 risk allele but heterozygous for DPB1*0101, an allele claimed to be an additional risk allele. We reasoned that if DPB1*0101 would not play a role in CD, then patients should inherit the DQ2 haplotypes randomly from a homozygous parent. We here present evidence that, in all 6 informative families, those DQ2 positive haplotypes that also include the DPB1*0101 allele, rather than those without DPB1*0101, are predominantly segregated to the index patient from the parent homozygous for the DQ2 risk marker (p = 0.03 as compared to their healthy siblings). If confirmed in larger studies the results indicate that despite DQ2 other genes in or near the MHC may associate with CD.

Celiac Disease↗

Effects of acute alcohol ingestion on heart rate variability in patients with documented coronary artery disease and stable angina pectoris.

The effects of acute alcohol intake (ethanol blood concentration 1.3 +/- 0.4%) on heart rate variability were evaluated with 24-hour Holter recordings in 20 patients with stable coronary artery disease in a juice-controlled experiment. In the frequency domain analysis, the high-, low-, and very low frequency components were significantly decreased after alcohol: these changes last longer than the elimination of alcohol.

Adult↗

Divergent association of apolipoprotein E polymorphism with vascular disease in patients with NIDDM and control subjects.

We analysed a well-characterized group of 83 patients (43 men, 40 women; mean age +/- SEM: 65.5 +/- 0.6 years at the 10-year examination) with non-insulin-dependent (Type 2) diabetes mellitus (NIDDM) and in 123 control subjects (56 men, 67 women; mean age +/- 0.9 years) retrospectively for the relationship of apolipoprotein E (apo E) genotypes (E2/3, E3/3 vs E3/4, E4/4) to the incidence of clinical macrovascular disease and its risk factors and the incidence of microvascular complications of diabetes during the first 10 years of NIDDM, as well as carotid intima-media thickness measured by B-mode ultrasound at the 10-year examination. In patients with NIDDM, apo E4 genotype showed no relationship to clinical events or carotid intima-media thickness. However, in the control subjects with apo E4, the incidence of non-fatal myocardial infarction during the follow-up was increased (apo E4 positivity: 17.1%; apo E4 negativity 5.1%; p = 0.035) and they had higher common carotid intima-media thickness than those with apo E2/3 or apo E3/3 (1.15 +/- 0.05 mm vs 1.01 +/- 0.03 mm, p = 0.008). Apo E genotype groups showed no relationship to microvascular complications of diabetes, although control subjects with apo E4 positivity showed a higher frequency of microalbuminuria than those lacking apo E4. We conclude that apo E4 was a marker of vascular disease and increased atherosclerosis in non-diabetic subjects, whereas in the diabetic patients these relationships were absent. It is likely that NIDDM per se influences the vascular risk so overwhelmingly that the effects of other risk factors are obscured.

Alleles↗

Relationship between EEG reactivity and neuropsychological tests in vascular dementia.

17 patients with vascular dementia (VaD) representing moderate to severe stage of the disease and 11 age-matched control subjects were examined with spectral analysis of EEG and a neuropsychological test battery comprising visual, praxic, verbal and memory functions as well as Mini-Mental Status test. VaD patients did not have less activity in the alpha band than control subjects, but the alpha amplitude ratio between eyes closed (EC) and eyes open (EO) situations (EC/EO ratio) was decreased in VaD patients, compared to controls. In VaD the variables of the awake background EEG with eyes closed (amplitude of alpha, beta, theta and delta activity; mean frequency) had only a few correlations to neuropsychological test scores. However, the (EC)/(EO) alpha ratio showed significant correlations with several neuropsychological variables in the temporo-occipital and centro-parietal derivations and some of these correlations were lateralized to the left or right hemisphere. Frontal EEG derivations with less alpha activity did not reveal any correlations to neuropsychological variables. We conclude that the dynamic EC/EO alpha ratio variable may be even more sensitive in the assessment of brain dysfunction in VaD than the background EEG variables.

Aged↗

The ability of THA treatment to increase cortical alpha waves is related to apolipoprotein E genotype of Alzheimer disease patients.

In a previous study, we reported that Alzheimer disease (AD) patients with an apolipoprotein E (APOE) epsilon 4 allele (+ APOE4) show more severe loss of nucleus basalis (NB) cholinergic cells than patients without epsilon 4 alleles (-APOE4). The present study investigates the effects of a single oral administration of THA 25 or 50 mg on cortical spectral EEG activity in + (five APOE4/4, six APOE4/3) and -APOE4 (eight APOE3/3) AD patients. THA 25 mg had no significant effect on EEG activity in any AD patients. However, THA 50 mg increased alpha activity and alpha/theta ratio in -APOE4 patients. In contrast, THA 50 mg had no effect on EEG activity in + APOE4 patients. This result tentatively suggests that in AD patients APOE genotype may affect the response of cortical electrical arousal to cholinergic therapy that enhances the efficacy of presynaptic NB axons.

Aged↗

THA disrupts mismatch negativity in Alzheimer disease.

The present study investigates the effects of 25 or 50 mg tetrahydroaminoacridine (THA), a cholinesterase inhibitor, on auditory mismatch negativity (MMN) event-related response in 19 patients with Alzheimer disease (AD). MMN is produced by the deviant tones representing passive attention and automatic detection of stimulus change. In an inattentive task condition, standard (85%) and deviant (15%) tones were represented in a random order with interstimulus interval of 1 s in separate blocks. THA 25 mg had no effect on MMN in AD patients. In contrast, THA 50 mg diminished MMN in AD subjects. The results suggests that acute treatment of AD subjects with a cholinesterase inhibitor disrupts the passive detection of change in an auditory input.

Aged↗

Mutation-haplotype analysis of steroid 21-hydroxylase (CYP21) deficiency in Finland. Implications for the population history of defective alleles.

Congenital adrenal hyperplasia (CAH) due to steroid 21-hydroxylase deficiency is a common inherited defect of adrenal steroid hormone biosynthesis. Unusually for genetic disorders, the majority of mutations causing CAH apparently result from recombinations between the CYP21 gene encoding the 21-hydroxylase enzyme and the closely linked, highly homologous pseudogene CYP21P. The CYP21 and CYP21P genes are located in the major histocompatibility complex class III region on chromosome 6p21.3. We analyzed the mutations and recombination breakpoints in the CYP21 gene and determined the associated haplotypes in 51 unrelated Finnish families with CAH. They represent no less than half of all CYP21 deficiency patients in Finland. The results indicate the existence of multiple founder mutation-haplotype combinations in the population of Finnish CAH patients. The three most common haplotypes constituted half of all affected chromosomes; only one-sixth of the haplotypes represented single cases. Each of the common haplotypes was shown consistently to carry a typical CYP21 mutation and only in some cases was additional variation observed. Surprisingly, comparisons with previous published data revealed that several of the frequent mutation-haplotype combinations in Finland are in fact also found in many other populations of patients of European origin, thus suggesting that these haplotypes are of ancient origin. This is in clear contrast to many reports, including the present one, where a high frequency of de novo mutations in the CYP21 gene has been reported. In addition, two unique sequence aberrations in CYP21 (W302X and R356Q), not known to exist in the CYP21P pseudogene, were detected.

Adrenal Hyperplasia, Congenital↗