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Biomedical subjects

R Zahn

Publications and source records attributed to R Zahn.

At least 55 records · Page 3Linked to original sources
PubMed2001

Effect of preinfarction angina pectoris on outcome in patients with acute myocardial infarction treated with primary angioplasty (results from the Myocardial Infarction Registry.

Preinfarction angina is associated with better clinical outcome in patients with acute myocardial infarction (AMI) who receive intravenous thrombolysis. This has not been proved in patients with AMI treated with primary angioplasty. We analyzed the data of the prospective multicenter Myocardial Infarction Registry (MIR). Of 14,440 patients with AMI, 774 with a prehospital delay of < or =12 hours were treated with primary angioplasty. Five hundred thirty-two patients (68.7%) had preinfarction angina. Patients with preinfarction angina were slightly older than patients without (63 vs 62 years, p = 0.042), prehospital delay was 1 hour longer (180 vs 120 minutes, p = 0.001), and arterial hypertension was more prevalent (47.6% vs 32.2%, odds ratio [OR] 1.91, 95% confidence intervals [CI] 1.39 to 2.62). There was no significant difference in hospital mortality (5.6% vs 3.3%, OR 1.75, 95% CI 0.79 to 3.87), reinfarction, stroke, or the combined end point of death, reinfarction, or stroke between the 2 groups. Logistic regression analysis showed no association of preinfarction angina with the occurrence of either death (OR 2.21, 95% CI 0.91 to 6.08) or the combined end points (OR 1.10, 95% CI 0.55 to 2.31). There was also no significant difference in mortality (6% vs 5.1%, OR 1.19, 95% CI 0.56 to 2.52), reinfarction, stroke, postinfarction angina, or the combined end points between patients with preinfarction angina within 48 hours compared with patients with preinfarction angina between 49 hours and 4 weeks before the AMI. Thus, the MIR data showed no protective effects of preinfarction angina in patients with AMI treated with primary angioplasty.

Angina Pectoris↗
PubMed2001

Polymorphisms of the ICAM-1 gene are associated with inflammatory bowel disease, regardless of the p-ANCA status.

The intercellular adhesion molecule-1 (ICAM-1) is of paramount importance for the initiation and propagation of various inflammatory conditions. An increased frequency of allele R241 of the ICAM-1 gene was previously described in p-ANCA-negative as compared to p-ANCA-positive ulcerative colitis and vice versa in Crohn's disease. One hundred sixteen healthy unrelated controls, 121 patients with ulcerative colitis, and 96 patients with Crohn's disease were genotyped for two polymorphisms of the ICAM-1 gene (R/G241, exon 4; and K/E469, exon 6), employing dot-blot hybridization and stratified according to their p-ANCA status. When compared with the control group the frequency of the allele R241 (P = 0.024) and the heterozygous genotype R/G241, P = 0.032) were significantly increased in ulcerative colitis, whereas the homozygous genotype G/G241 was found less frequently (P = 0.022). The heterozygous genotype K/E469 was observed less frequently (P = 0.001 and 0.037, resp.) than the homozygous genotype E/E469, which was more frequent in Crohn's disease and ulcerative colitis (P = 0.002 and 0.012, respectively). Further significant differences concerning the allele or genotype distribution were not observed. After stratification for the p-ANCA status significant differences concerning the frequencies of both the R241 and the E469 alleles were not detected when p-ANCA-positive inflammatory bowel disease and p-ANCA-negative inflammatory bowel disease were compared. Ulcerative colitis and Crohn's disease are associated with polymorphisms of the ICAM-1 gene, which might therefore represent a functional candidate gene. However, the observed associations are independent of the p-ANCA status.

Alleles↗
PubMed2001

Identification of a novel HLA-B*2722 allele from a Filipino cell.

We present the novel HLA-allele B*2722 amplified and sequenced from a Filipino individual. This DNA was included several times in the International Cell Exchange, UCLA, and typed at the time as B*27 or B*2706 by the majority of the participating laboratories. The second HLA-B allele of this person is B*3802. B*2704/06 or B*2704/06/10 were suggested by approximately one-third of the laboratories. As we were investigating the intron 3 sequences of B*27 alleles, we also sequenced exon 4 of this Filipino DNA and found a single nucleotide exchange in exon 4 (pos. 704) which was not in concordance with the previous B*2706 typing. Our sequencing results showed that the coding sequence of B*2722 is identical to B*2706 in exon 1, 2 and 3. In exon 4 the B*2722 sequence is identical to B*2704. HLA-B*2704 differs from B*2706 in one base at position 704, a G in B*2704 and a C in B*2706, respectively.

Alleles↗
PubMed2001

Vrp1p functions in both actomyosin ring-dependent and Hof1p-dependent pathways of cytokinesis.

Vrp1p/verprolin/End5p is a Saccharomyces cerevisiae proline-rich protein, structurally and functionally related to human Wiskott-Aldrich syndrome protein-interacting protein. Vrp1p is required for viability at 37 degrees C, but not 24 degrees C. Here, we show that loss of Vrp1p (vrp1Delta) leads to a 3-4-fold delay in cytokinesis, wide bud necks, abnormal actomyosin rings, and aberrant septa even at 24 degrees C. Like other mutations affecting the actomyosin ring, vrp1Delta is synthetic lethal with deletion of HOF1 (or CYK2), which encodes a protein related to mammalian proline serine threonine phosphatase-interacting protein and Schizosaccharomyces pombe Cdc15p required for an actomyosin ring-independent pathway of cytokinesis in S. cerevisiae. At 37 degrees C, vrp1Delta cells rapidly cease dividing and exhibit a novel terminal phenotype: a single large bud, two well-separated nuclei, and an interphase microtubule array. The arrested cells have a persistent ring containing both actin and myosin at the bud neck. Many also exhibit some polarisation of cortical actin patches to the bud neck. Vrp1p binds an SH3-domain-containing fragment of Hof1p in vitro. Vrp1p is required in vivo for Hof1p relocalisation to a single ring at the bud neck prior to cytokinesis at 37 degrees C, but not at 24 degrees C. Vrp1p thus acts in both actomyosin ring formation and function, as well as in Hof1p localisation during cytokinesis.

Actomyosin↗
PubMed2001

Differences in treatment and outcome of patients with acute myocardial infarction admitted to hospitals with compared to without departments of cardiology; results from the pooled data of the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA 1+2) Registries and the Myocardial Infarction Registry (MIR).

AIMS: The specialty of the admitting physician may influence treatment and outcome in patients with acute myocardial infarction. METHODS AND RESULTS: The pooled data of three German acute myocardial infarction registries: the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) 1+2 studies and the Myocardial Infarction Registry (MIR) were analysed. Patients admitted to hospitals with departments of cardiology were compared to hospitals without such departments. A total of 24 814 acute myocardial infarction patients were included, 9020 (36%) patients at 91 (29.8%) hospitals with departments of cardiology and 15 794 (64%) at 214 (70.2%) hospitals without cardiology departments. There were only minor differences in patient characteristics and prevalence of concomitant diseases between the two types of hospital. The first electrocardiogram was more often diagnostic at hospitals with cardiology departments (71.8% vs 66.5%, P<0.001). Reperfusion therapy and adjunctive medical therapy, such as aspirin, beta-blockers and ACE-inhibitors were used more often at cardiology departments (all P -values <0.001), even after adjustment for confounding parameters. Treatment improved at both types of hospital over time. Admission to a hospital with a department of cardiology was independently associated with a lower hospital mortality (14.2% vs 15.4%, adjusted OR=0.91; 95%CI: 0.83-0.99). Additional logistic regression models showed that the higher use of reperfusion therapy and recommended concomitant medical therapy was responsible for most of the survival benefit at such hospitals. CONCLUSION: Treatment of acute myocardial infarction patients at hospitals with departments of cardiology was independently associated with a higher use of recommended therapy and a lower hospital mortality compared to hospitals without such departments.

Aged↗
PubMed2001

Characterization and clinical course of patients not receiving aspirin for acute myocardial infarction: results from the MITRA and MIR studies.

BACKGROUND: Clinical trials have shown the efficacy of aspirin for acute myocardial infarction (AMI). However, not all patients receive aspirin for AMI. The aim of this study was to provide information on characteristics and clinical course of patients not treated with aspirin for AMI. METHODS: We analyzed the data of the Myocardial Infarction Registry (MIR) and the Maximal Individual Therapy of Acute Myocardial Infarction (MITRA) registry. MITRA and MIR were prospective multicenter registries of patients with ST segment elevation myocardial infarction in Germany. RESULTS: Of 22,572 patients registered from 1994 to 1998, 1767 (7.8%) did not receive aspirin within the first 48 hours after admission. Multivariate analysis revealed two main factors associated with withholding aspirin for AMI: relative contraindications to aspirin (gastric ulcer [odds ratio (OR) 4.9, 95% confidence interval (CI) 3.7-5.7], renal insufficiency [OR 1.4, 95% CI 1.1-1.8]), and critical clinical state at admission (cardiogenic shock [OR 1.5, 95% CI 1.2-2.1] and prehospital resuscitation [OR 1.8, 95% CI 1.4-2.2]). In addition, these patients were significantly less likely to receive reperfusion therapy and adjunctive medical therapy such as beta-blockers and angiotensin-converting enzyme inhibitors. In-hospital mortality after adjustment for baseline characteristics was 27.2% in patients without aspirin compared with 11.1% in patients treated with aspirin. CONCLUSIONS: Only a minority of AMI patients (7.8%) did not receive aspirin. Relative contraindications to aspirin and a critical clinical state at admission were the main factors associated with withholding aspirin for AMI. Even after adjustment for patient characteristics, the mortality of patients without aspirin was almost three times higher.

Aged↗
PubMed2001

Impact of prehospital delay on mortality in patients with acute myocardial infarction treated with primary angioplasty and intravenous thrombolysis.

BACKGROUND: In patients with acute myocardial infarction treated with thrombolysis, longer times to treatment are associated with increasingly worse clinical outcome. This relation may be different for treatment with primary angioplasty. METHODS: We analyzed the pooled data of the German acute myocardial infarction registries Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) and Myocardial Infarction Registry (MIR) to determine the influence of prehospital delays on hospital mortality rates. Primary angioplasty was performed in 1063 patients and thrombolysis in 7552 patients. RESULTS: In patients treated with thrombolysis, in-hospital time to treatment was constantly 30 minutes median. In patients treated with primary angioplasty, in-hospital time to treatment increased from 60 minutes median up to 87 minutes median with increasing prehospital delay. Hospital mortality rates slightly decreased with increasing prehospital delays in patients treated with primary angioplasty (P for trend =.02). However, in patients treated with thrombolysis, mortality rate was nonsignificantly increased (P for trend =.11). Logistic regression analysis showed no significant difference in mortality rates between primary angioplasty and thrombolysis for prehospital delays of <3 hours. However, when prehospital delay was >3 hours, thrombolysis was independently associated with a higher mortality rate compared with primary angioplasty. CONCLUSIONS: Compared with thrombolysis, primary angioplasty is independently associated with a lower mortality rate in prehospital delays of >3 hours. The reason for this may be a time-dependent loss of efficacy to achieve reperfusion for thrombolysis but not for primary angioplasty.

Angioplasty, Balloon↗
PubMed2001

Asymmetries of visual attention after circumscribed subcortical vascular lesions.

OBJECTIVE: To investigate the role of the basal ganglia and the thalamus for basic processes of visuospatial attention METHODS: Fifteen patients with acute circumscribed vascular lesions (10 with haemorrhage and five with infarction) were included in the study. The lesions were confined exclusively to subcortical structures, such as the basal ganglia, internal capsule, and thalamus, which was confirmed by initial CT on the day of referral and MRI taken 14-28 days after clinical onset. These patients were examined with two computerised attentional tasks (one detection and one search task) measuring spatial visual attention. RESULTS: There was a clear attentional asymmetry in patients with right hemispheric lesions (RHLs) in the visual search task. Seven out of eight patients with RHLs tended to be slower and/or missed significantly more target stimuli in the left sided part of a stimulus array consisting of 25 small squares than in right sided parts, although none of these patients showed signs of visual hemineglect in the visual detection task presenting visual information simultaneously to the right and left visual hemispace. All but one of these patients showed lesions in the posterior limb of the internal capsule and the putamen. On the other hand, patients with left hemispheric lesions were not impaired in the search task with only one patient showing more contralesional omissions of target stimuli than could be expected from the behaviour of normal controls. CONCLUSIONS: The results are in line with previous results showing a dominant role of right hemispheric neuronal structures for spatial attention. Furthermore, the data suggest that even with right hemispheric subcortical lesions without cortical involvement deficits in spatial orienting of attention to the left hemispace can be seen. These asymmetries of visual attention in the absence of neglect symptoms are supposed to be caused (1) by a disruption of the motor corticostriato-pallidothalamo-cortical neuronal circuit or (2) by a (partial) disconnection of relevant parts within the posterior attention network-namely, parietal and thalamic structures.

Adult↗
PubMed2001

End13p/Vps4p is required for efficient transport from early to late endosomes in Saccharomyces cerevisiae.

end13-1 was isolated in a screen for endocytosis mutants and has been shown to have a post-internalisation defect in endocytic transport as well as a defect in vacuolar protein sorting (Vps(-) phenotype), leading to secretion of newly synthesised vacuolar proteins. Here we demonstrate that END13 is identical to VPS4, encoding an AAA (ATPase associated with a variety of cellular activities)-family ATPase. We also report that the end13-1 mutation is a serine 335 to phenylalanine substitution in the AAA-ATPase domain of End13p/Vps4p. It has been reported that mutant cells lacking End13p/Vps4p (end13(vps4)Delta) accumulate endocytosed marker dyes, plasma membrane receptors and newly synthesised vacuolar hydrolase precursors in an endosomal compartment adjacent to the vacuole (prevacuolar compartment, or PVC). We find, however, that the end13 mutants have defects in transport of endocytosed fluorescent dyes, plasma membrane receptors and ligands from small peripherally located early endosomes to larger late endosomes, which are often located adjacent to the vacuole. Our results indicate that End13p/Vps4p may play an important role in multiple steps of membrane traffic through the endocytic pathway.

Adenosine Triphosphatases↗
PubMed2001

Primary angioplasty versus no reperfusion therapy in patients with acute myocardial infarction and a pre-hospital delay of > 12-24 hours: results from the pooled data of the maximal individual therapy in acute myocardial infarction (MITRA) registry and the myocardial infarction registry (MIR).

OBJECTIVE: In patients with acute myocardial infarction (AMI), treatment with thrombolysis is superior to no reperfusion therapy only up to 12 hours after the onset of symptoms. There are no data addressing whether this time limit is also justified for treatment with primary angioplasty. DESIGN: The pooled data of two German ST-segment elevation AMI registries, the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) study and the Myocardial Infarction Registry (MIR), were analyzed. PATIENTS: Out of 22,749 patients, eight hundred and forty-eight with a pre-hospital delay of > 12 hours and < or = 24 hours were treated with either primary angioplasty (94/848; 11.1%) or no reperfusion therapy (754/848; 88.9%). RESULTS: Patients treated with primary angioplasty were 10 years younger (59 years versus 69 years; p = 0.001), more often male [72.3% versus 59.9%; odds ratio (OR) = 0.57; 95% confidence interval (CI) = 0.36-0.92] and less likely to be diabetics (17% versus 27.2%; OR = 0.55; 95% CI = 0.31-0.97). Hospital mortality was 8.5% in patients treated with primary angioplasty compared to 17.1% in patients with no reperfusion therapy (OR = 0.45; 95% CI = 0.21-0.95; p = 0.033) and the combined endpoint (death, reinfarction or stroke) occurred significantly less often (11.7% versus 20.3%; OR = 0.52; 95% CI =0.27-1; p = 0.045). However, multiple logistic regression showed only a non-significant trend for lower mortality (OR = 0.54; 95% CI =0.20-1.23) and the combined endpoint (OR = 0.65; 95% CI = 0.29-1.31) in patients treated with primary angioplasty. CONCLUSIONS: These data show the possibility of a benefit of primary angioplasty over conservative treatment in patients with pre-hospital delays of > 12 up to 24 hours, although multiple logistic regression analysis failed to find significant differences between treatments. This might be due to inadequate study power or a selection bias. These findings encourage further investigation of this subject.

Age Factors↗
PubMed2000

Molecular cloning and expression of human UDP-d-Xylose:proteoglycan core protein beta-d-xylosyltransferase and its first isoform XT-II.

Human UDP-d-xylose:proteoglycan core protein beta-d-xylosyltransferase (EC 2.4.2.26, XT-I) initiates the biosynthesis of glycosaminoglycan chains in proteoglycans by transferring xylose from UDP-xylose to specific serine residues of the core protein. Based on the partial amino acid sequence of the purified enzyme from human JAR choriocarcinoma cell culture supernatant we isolated a cDNA encoding XT-I using the degenerate reverse transcriptase-polymerase chain reaction method. This enzyme, which is involved in chondroitin sulfate, heparan sulfate, heparin and dermatan sulfate biosynthesis, belongs to a novel family of glycosyltransferases with no homology to proteins known so far. 5' and 3'-RACE were performed to isolate a novel cDNA fragment of 3726 bp with a single open reading frame encoding at least 827 amino acid residues with a molecular mass of 91 kDa. The human XT-I gene was located on chromosome 16p13.1 using radiation hybrid mapping, and extracts from CHO-K1 cells transfected with the XT-I cDNA in an expression vector exhibited marked XT activity. A new 3608 bp cDNA fragment encoding a protein of 865 amino acid residues was also isolated by PCR using degenerate primers based on the amino acid sequence of human XT-I. The amino acid sequence of this XT-II isoform displayed 55% identity to the human XT-I. The XT-II gene was located on chromosome 17q21.3-17q22, and the exon/intron structure of the 15 kb gene was determined. RT-PCR analyses of XT-I and XT-II mRNA from various tissues confirmed that both XT-I and XT-II transcripts are ubiquitously expressed in the human tissues, although with different levels of transcription. Furthermore, the cDNAs encoding XT-I and XT-II from rat were cloned. The deduced amino acid sequences of rat xylosyltransferases displayed 94% identity to the corresponding human enzyme.

Amino Acid Sequence↗
PubMed2000

[Comparison of acute myocardial infarct in the old and new lands of unified Germany, 1996-1998. Data of the Myocardial Infarct Register (MIR)].

BACKGROUND AND OBJECTIVE: Little is known about any differences in the prevention, treatment and treatment results of myocardial infarction between the "old" (western) and "new" (eastern) Lands (OFL vs. NFL) of the now unified Federal Republic of Germany. It was the aim of this study to determine any such differences. PATIENTS AND METHODS: The Myocardial Infarction Register (MIR) is a multicentre and prospective compilation of consecutive unselected data on patients with acute myocardial infarction sustained between December 1996 and May 1998. All date collected between these dates were included in the study: there were 14,608 patients in 211 hospitals, 5618 patients and 68 hospitals of those in the eastern part (former German Democratic Republic). The median age of the entire collective was 68 years, 35% of patients were female. RESULTS: There was a higher prevalence of risk factors in the NFL than the OFL: 43.3 vs. 39.0% with regard to arterial hypertension (p = 0.002), and 28.9 vs. 22.4% with regard to diabetes mellitus (p < 0.001). The prehospital period was longer in the NFL by an average of 30 min (210 vs. 180 min; p < 0.001. Another difference concerned the lower number of diagnostic ECGs in the NFL (61.8 vs. 68.6%; p < 0.001). There were no significant differences with regard to acute and discharge medication (acetylsalicylic acid, betablockers, angiotensin-converting-enzyme inhibitors and cholesterol-synthesis inhibitors). The frequency of primary recanalization treatment (thrombolysis or percutaneous transluminal coronary angioplasty) in patients with clear-cut indications for thrombolysis was higher in the OFL (85.1 vs. 74.5%; p < 0.001). Hospital mortality was comparable (15.1 vs. 15.9%; p = 0.14). CONCLUSION: Patient characteristics and treatment in the two parts of Germany were comparable in the two parts. Treatment of acute myocardial infarction attained a similarly high standard in both. But in both parts there is room for improving the application of guidelines for treating of myocardial infarction to routine clinical practice. Greater effort should be made to inform the population, especially of the NFL, about the need for primary prevention and reduction in prehospital time.

Adrenergic beta-Antagonists↗
PubMed2000

[Current use and outcomes of intraaortic balloon counterpulsation in routine cardiology].

BACKGROUND: Intraaortic balloon counterpulsation (IABC) is an established technique for temporary support of the left ventricular function. However, less is known about the current use and outcome of IABC in daily clinical practice. PATIENTS AND METHOD: From July 1995 to May 1999 all patients receiving an IABC in the Department of Cardiology of the Heart Center Ludwigshafen were included in a consecutive registry and follow-up data were obtained. RESULTS: Sixty-six patients (mean age 65 years, 64% male) received an IABC during the registration period. In 95% of cases the indication for IABC was the presence of cardiogenic shock. The shock was due to an acute myocardial infarction in 83%, other reasons were less frequent (< or = 5%). Total inhospital mortality was 48%. Patients in shock due to myocardial infarction (53%) showed the highest mortality. During follow-up (median 20 months) another 21% died. Complications occurred in 20% of patients under IABC, including vascular complications in 12%, infections in 5% and major bleedings in 3%. There was no difference between mortality among patients with complications and total mortality. CONCLUSION: Main indication for IABC in daily practice is the presence of cardiogenic shock (95%), dominantly due to myocardial infarction (83%). Despite IABC therapy, half of these patients die during the hospital stay. High mortality of cardiogenic shock in myocardial infarction with pharmacological therapy justifies IABC treatment with regard to a rate of complications of 20%.

Adult↗
PubMed2000

NMR structure of the bovine prion protein.

The NMR structures of the recombinant 217-residue polypeptide chain of the mature bovine prion protein, bPrP(23-230), and a C-terminal fragment, bPrP(121-230), include a globular domain extending from residue 125 to residue 227, a short flexible chain end of residues 228-230, and an N-terminal flexibly disordered "tail" comprising 108 residues for the intact protein and 4 residues for bPrP(121-230), respectively. The globular domain contains three alpha-helices comprising the residues 144-154, 173-194, and 200-226, and a short antiparallel beta-sheet comprising the residues 128-131 and 161-164. The best-defined parts of the globular domain are the central portions of the helices 2 and 3, which are linked by the only disulfide bond in bPrP. Significantly increased disorder and mobility is observed for helix 1, the loop 166-172 leading from the beta-strand 2 to helix 2, the end of helix 2 and the following loop, and the last turn of helix 3. Although there are characteristic local differences relative to the conformations of the murine and Syrian hamster prion proteins, the bPrP structure is essentially identical to that of the human prion protein. On the other hand, there are differences between bovine and human PrP in the surface distribution of electrostatic charges, which then appears to be the principal structural feature of the "healthy" PrP form that might affect the stringency of the species barrier for transmission of prion diseases between humans and cattle.

Amino Acid Sequence↗
PubMed2000

NMR structures of three single-residue variants of the human prion protein.

The NMR structures of three single-amino acid variants of the C-terminal domain of the human prion protein, hPrP(121-230), are presented. In hPrP(M166V) and hPrP(R220K) the substitution is with the corresponding residue in murine PrP, and in hPrP(S170N) it is with the corresponding Syrian hamster residue. All three substitutions are in the surface region of the structure of the cellular form of PrP (PrP(C)) that is formed by the C-terminal part of helix 3, with residues 218-230, and a loop of residues 166-172. This molecular region shows high species variability and has been implicated in specific interactions with a so far not further characterized "protein X," and it is related to the species barrier for transmission of prion diseases. As expected, the three variant hPrP(121-230) structures have the same global architecture as the previously determined wild-type bovine, human, murine, and Syrian hamster prion proteins, but with the present study two localized "conformational markers" could be related with single amino acid exchanges. These are the length and quality of definition of helix 3, and the NMR-observability of the residues in the loop 166-172. Poor definition of the C-terminal part of helix 3 is characteristic for murine PrP and has now been observed also for hPrP(R220K), and NMR observation of the complete loop 166-172 has so far been unique for Syrian hamster PrP and is now also documented for hPrP(S170N).

Amino Acid Sequence↗
PubMed2000

Hemispheric lateralization at different levels of human auditory word processing: a functional magnetic resonance imaging study.

We used functional magnetic resonance imaging to disentangle the functional anatomy of brain systems involved in the processing of auditory word form and meaning. Three monitoring tasks on auditory stimuli, aimed at phonetic, lexical and semantic processing, were used. We found no lateralization of temporal lobe activations, when word processing was contrasted versus the complex phonetic task. Bilateral middle temporal activations (Brodmann Area [BA] 21) were attributed to processing of word-form. Areas specific to semantic processing were restricted to the left hemisphere: the posterior middle frontal (BA 9) and posterior parietal (BA 7/40) cortex, as well as an inferior temporal area (BA 20/21). Our data suggest, that left hemispheric dominance for auditory word comprehension occurred at the level of semantic processing.

Acoustic Stimulation↗
PubMed2000

NMR solution structure of the human prion protein.

The NMR structures of the recombinant human prion protein, hPrP(23-230), and two C-terminal fragments, hPrP(90-230) and hPrP(121-230), include a globular domain extending from residues 125-228, for which a detailed structure was obtained, and an N-terminal flexibly disordered "tail." The globular domain contains three alpha-helices comprising the residues 144-154, 173-194, and 200-228 and a short anti-parallel beta-sheet comprising the residues 128-131 and 161-164. Within the globular domain, three polypeptide segments show increased structural disorder: i.e., a loop of residues 167-171, the residues 187-194 at the end of helix 2, and the residues 219-228 in the C-terminal part of helix 3. The local conformational state of the polypeptide segments 187-193 in helix 2 and 219-226 in helix 3 is measurably influenced by the length of the N-terminal tail, with the helical states being most highly populated in hPrP(23-230). When compared with the previously reported structures of the murine and Syrian hamster prion proteins, the length of helix 3 coincides more closely with that in the Syrian hamster protein whereas the disordered loop 167-171 is shared with murine PrP. These species variations of local structure are in a surface area of the cellular form of PrP that has previously been implicated in intermolecular interactions related both to the species barrier for infectious transmission of prion disease and to immune reactions.

Animals↗