Heterogeneity of protein profiles of Helicobacter pylori isolated from individual patients

A standardized neuropsychological test battery was administered to 167 patients with different forms of mild-to-moderate dementia: probable Alzheimer dementia (AD: n = 49), multi-infarct dementia (n = 43), idiopathic Parkinson disease with dementia (n = 35), depressive pseudodementia (n = 26), and progressive supranuclear palsy (n = 14). Results obtained were used (a) to analyze the profiles of cognitive impairment shown by the different dementia groups; (b) to assess the incidence of some neuropsychological patterns that we hypothesized to be more characteristic of AD, in the various groups; and hence (c) to evaluate the reliability of these patterns as diagnostic markers of AD. Four of the patterns investigated were derived from a verbal learning task (Rey's Auditory Verbal Learning test): (1) absence of the primacy effect; (2) tendency to produce intrusion errors during free recall of a word list; (3) absolute decay of memory trace; and (4) tendency to produce false alarms during delayed recognition of the same word list. Two additional patterns were derived from visual-spatial tasks (copying drawings and Raven's Coloured Progressive Matrices): (5) occurrence of the closing-in phenomenon in copying drawings; and (6) tendency to choose globalistic or odd responses in Raven's matrices. Though all the six patterns were somewhat useful for identifying AD patients, no pattern met the criteria of being both highly sensitive and highly specific, which should characterize an ideal marker. In fact, intrusions and false alarms were observed in many AD patients, but also in patients affected by other forms of dementia. The absence of the primacy effect, the closing-in phenomenon, and the absolute decay of memory trace were more specific, but could be observed in only one-third of AD patients. We also computed the number of positive patterns shown by each patient and assumed the presence of two or more patterns as a global index suggestive of a dementia of the Alzheimer type. With this cumulative method, a higher level of sensitivity and specificity was achieved in the identification of AD patients.     

Thermal unfolding of the starch binding domain of Aspergillus niger glucoamylase

A fragment of the starch-binding domain (SBDF) of Aspergillus niger glucoamylase was prepared using recombinant DNA techniques, and its thermal unfolding was investigated by high-sensitivity differential scanning calorimetry (DSC). Thermal unfolding of SBDF was found to be reversible at pH 7 as expected from a DSC study of the whole enzyme molecule [Tanaka A. et al., J. Biochem., 117, 1024-1028 (1995)] but not reversible at acidic region. Numerical analysis of the DSC curves showed that the denaturation was two-state, and some of the SBDF molecules were oligomeric (average degree of oligomerization was 1.2) at pH 7. It was suggested that the denaturation temperature of SBDF was lower than that of the starch-binding domain in the whole enzyme molecule by about 4.5 degrees (decrease in the Gibbs energy change was 5.3 kJ mol-1) indicating a possibility that the starch-binding domain is stabilized by glycosylation of the domain itself, or by the highly glycosylated linker region.     

Codon 219 Lys allele of PRNP is not found in sporadic Creutzfeldt-Jakob disease

OBJECTIVE: To determine the prevalence of hypergastrinemia in cats with naturally developing chronic renal failure (CRF) and the correlation between gastrin concentration in plasma and severity of CRF. DESIGN: Cohort study. ANIMALS: 30 cats with naturally developing CRF and 12 clinically normal control cats. PROCEDURE: Gastrin concentrations in plasma were determined by double-antibody radioimmunoassay of blood samples obtained from cats after food was withheld 8 hours. Concentrations were compared, using a nonparametric Kruskal-Wallis ANOVA. RESULTS: 18 cats with CRF had high gastrin concentrations (median, 45 pg/ml; range, < 18 to > 1,333 pg/ml), compared with those for control cats (< 18 pg/ml). Prevalence of hypergastrinemia increased with severity of renal insufficiency. Three of 9 cats with mild CRF, 6 of 11 cats with moderate CRF, and 9 of 10 cats with severe CRF had high gastrin concentrations. Gastrin concentrations were significantly different between control cats and cats with CRF, regardless of disease severity. CLINICAL IMPLICATIONS: The potential role of high concentrations of gastrin on gastric hyperacidity, uremic gastritis, bleeding from the gastrointestinal tract, and associated clinical signs of hypergastrinemia (e.g., anorexia and vomiting) may justify use of histamine2-receptor antagonists or proton pump inhibitors to suppress gastric acid secretion in cats with CRF that have these clinical signs.     

Spatio-Temporal Data Mining for Typhoon Image Collection

Our research aims at discovering useful knowledge from the large collection of satellite images of typhoons using data mining approaches. We first introduce the creation of the typhoon image collection that consists of around 34,000 typhoon images for the northern and southern hemisphere, providing the medium-sized, richly-variational and quality-controlled data collection suitable for spatio-temporal data mining research. Next we apply several data mining approaches for this image collection. We start with spatial data mining, where principal component analysis is used for extracting basic components and reducing dimensionality, and it revealed that the major principal components describe latitudinal structures and spiral bands. Moreover, clustering procedures give the birds-eye-view visualization of typhoon cloud patterns. We then turn to temporal data mining, including state transition rules, but we demonstrate that it involves intrinsic difficulty associated with the nonlinear dynamics of the atmosphere, or chaos. Finally we briefly introduce our system IMET (Image Mining Environment for Typhoon analysis and prediction), which is designed for the intelligent and efficient searching and browsing of the typhoon image collection.     

Mutation in the prion protein gene at codon 232 in Japanese patients with Creutzfeldt-Jakob disease: a clinicopathological, immunohistochemical and transmission study

The societal and economic forces driving change in medical education are affecting communities as well as universities. Each of the four authors of this paper is deeply involved in one of the components of their locale's well-developed community-based medical educational system, and each describes how change is influencing his role in that system, whether the role be managing a community hospital, directing a local Area Health Education Center, participating as a family medicine faculty member, or being a community preceptor. They agree on some common themes: (1) that it is good that medical students' education is moving into the community (e.g., this validates the importance of the community hospital to medical education, is an acknowledgment of the importance of generalism, and provides students invaluable learning experiences); (2) that educating medical students in the community is expensive, and more funding and resources are needed so that the area's hospitals, community faculty, preceptors, and support services can be fairly compensated for their commitment; and (3) that their community-based education system can no longer absorb the costs of training more medical students. This is not a criticism of academic medical centers, which are under tremendous financial pressures themselves, but is simply to state the community perspective and to urge fairness in the distribution of resources for medical education. Community institutions and academic medical centers will work individually to create their own integrated health care systems but must work together to create a better, more cost-effective system for educating medical students.     

Molecular cloning, purification and characterization of two endo-1,4-beta-glucanases from Aspergillus oryzae KBN616

Two endo-1,4-beta-glucanase genes, designated celA and celB, from a shoyu koji mold Aspergillus oryzae KBN616, were cloned and characterized. The celA gene comprised 877 bp with two introns. The CelA protein consisted of 239 amino acids and was assigned to the cellulase family H. The celB gene comprised 1248 bp with no introns. The CelB protein consisted of 416 amino acids and was assigned to the cellulase family C. Both genes were overexpressed under the promoter of the A. oryzae taka-amylase A gene for purification and enzymatic characterization of CelA and CelB. CelA had a molecular mass of 31 kDa, a pH optimum of 5.0 and temperature optimum of 55 degrees C, whereas CelB had a molecular mass of 53 kDa, a pH optimum of 4.0 and temperature optimum of 45 degrees C.     

Image Classification Using Probabilistic Models that Reflect the Internal Structure of Mixels

The purpose of this paper is to establish an image classification method which properly considers the spatial quantisation effect of digital imagery and its inevitable consequence, the presence of mixels. To achieve this goal, we propose two new probabilistic models, namely the area proportion distribution and mixel distribution. The former probabilistic model serves as the prior distribution of area proportions that reflect the internal structure of mixels, and Beta distribution is proposed as the general model of the area proportion distribution. On the other hand, the latter probabilistic model is a unique model both in concept and shape, and its uniqueness is the source of its effectiveness against an image histogram which can be represented by a set of trough and peak regions by means of the mixel distributions and pure pixel distributions, respectively. Moreover, the expected area proportion is proposed for computing the area proportions of mixels. Finally, experimental results on satellite image classification are analysed to validate the effectiveness of our proposed probabilistic models. By comparing the mixture density model with our proposed models to those without them, we conclude that, both in terms of quantitative and qualitative evaluation, our probabilistic models work effectively for images with the presence of mixels. Received: 10 November 1998?Received in revised form: 17 December 1998?Accepted: 18 December 1998     

Indications for palliative reduction surgery for hepatocellular carcinoma with multiple intrahepatic metastases

It is assumed that stenosis of the right coronary artery (RCA) predisposes CABG patients, by way of incomplete atrial myocardial protection, to postoperative atrial fibrillation (AF). Sixty patients with high-grade RCA lesion were randomized into four groups according to the technique of delivery of cold blood cardioplegia: antegrade, retrograde, retrograde without catheter cuff, and combined antegrade and retrograde. As controls, 34 patients without RCA lesion were randomized to receive antegrade or retrograde cardioplegia. Postoperative atrial fibrillation episodes were recorded. Patients with RCA lesion were more prone to develop AF; odds ratio (OR)=3.75 (95% confidence interval [CI]=1.22-11.5). Retrograde delivery in these patients was more often associated with AF, OR=4.97 (95% CI = 1.02-24.1). Other risk factors for AF were an increasing number of preoperative infarcts (p < 0.05) and more advanced coronary artery disease (p < 0.05). Prolonged stay in the intensive care unit (p < 0.001) and occurrence of postoperative ventricular tachycardia (p < 0.05) were associated with AF. RCA stenosis and retrograde cardioplegia delivery in RCA-affected patients were risk factors for postoperative atrial fibrillation. Retrograde cardioplegia may offer poorer protection at the atrial level.