Objective assessment of antianginal treatment: a double-blind comparison of propranolol,nifedipine, and their combination.

In a double-blind clinical trial the antianginal effects of nifedipine (30 and 60 mg/day) and propranolol 240 and 480 mg/day) and a combination of both drugs were compared with those of placebo in 16 patients with severe exertional angina pectoris. Response to treatment was assessed by the objective criteria of 16-point precordial exercise mapping and 48-hour ambulatory electrocardiographic monitoring and subjectively by analysis of patients'' daily diaries of episodes of angina and consumption of glyceryl trintrate. The incidence of pain and consumption of glyceryl trinitrate were significantly decreased by each drug compared with placebo, and the combination produced a further significant improvement. Objectively the total area and amount of ST depression on the precordial exercise map and the total number of episodes of ST depression detected on ambulatory monitoring confirmed the efficacy of each treatment regimen; the combination was significantly better than either drug alone (p <0.005). The objective methods permitted greater separation of treatment efficacy and showed reliably that the combination of propranolol and nifedipine was significantly better than either drug alone. Thus this combination is a safe and effective form of treatment for angina.     

Brugada syndrome manifested by the typical electrocardiographic pattern both in the right precordial and the high lateral leads

We identified a patient with the Brugada syndrome and frequent episodes of the traumatic syncope. This patient presented with alternating ST-segment elevation in the right precordial and the high lateral leads. The signal-averaged ECG was positive for the late potentials and electrophysiology study revealed no inducible supraventricular or ventricular tachycardias. Because of the frequent traumatic syncope, a dual-chamber implantable cardioverter-defibrillator was implanted. This report suggests that the Brugada syndrome may have different electrocardiographic presentations within a single individual over a short period of time. The significance of these changes needs to be assessed in a prospective long term study.     

Myocardial ischaemia in patients with frequent angina pectoris.

One hundred patients with angina pectoris underwent 16-point electrocardiographic (ECG) mapping of the left hemithorax during a standardised exercise test. Forty-five patients had maximum ST-segment depression at position V5, while 35 had no ECG signs of ischaemia at this position. In 20 V5 was on the edge of the precordial area, which showed less severe ST-depression than the central positions. An Oxford ECG recorder and highspeed analyser were modified and used in 50 of the patients with daily angina for recording ST-segment changes over 24 hours. Serial 24-hour ambulatory recordings from the edge of the precordial area of ischaemia identified during exercise detected a mean of only 14 +/- SD 3% of the episodes of ST-segment changes recorded from the centre of the same area. Only 16 +/- 2% of the episodes detected by ECG were accompanied by chest pain. More episodes occurred between 4 am and 6 am than at any other time during the night. This study shows the importance of recording ECG evidence of ischaemia from the precordial position showing maximum changes during exercise. ECG evidence of ischaemia occurs more frequently than anginal pain. These objective measurements add important information to the frequency of chest pain reported by patients with ischaemic heart disease.     

Influence of exercise training on spatial R-wave amplitude in patients with coronary artery disease

To evaluate the influence of an exercise program on spatial and left precordial R-wave amplitude among patients with coronary artery disease, computerized electrocardiogram (ECG) data were acquired during maximal treadmill testing before and after 1 yr in 89 patients randomized to either exercise (n = 40) or control (n = 49) groups. Spatial and lateral R-wave amplitudes were derived from the orthogonal Frank (XYZ) lead system. The exercise group significantly increased maximal O2 consumption (0.17 l/min), whereas controls decreased significantly (0.12 l/min, P less than 0.01 between groups). No significant changes in electrocardiographic R-wave voltage measurements occurred within or between groups during the year. It is concluded that exercise training does not result in increases in R-wave voltage in patients with coronary artery disease.     

A data mining approach for analyzing density maps representing macromolecular structures

Results of electron microscopy-based three-dimensional reconstructions of macromolecules or their complexes are usually stored as density maps. Each point ("voxel") in the map represents a density value and one approach for studying details of the map is to display an isosurface enclosing areas of interest. We have taken a data mining approach not only focusing on the areas of immediate interest but determining all possible separate entities ("blobs") from a density map. After the entire density map is analyzed with our mining program BLOBBER, properties of all detected blobs can be browsed and sets of blobs can be visualized using our VIZBLOB program. Since BLOBBER analyzes density maps using only density information and relates it to spatial relationships, BLOBBER can be used to analyze symmetrical or asymmetrical density maps from any source. To test our program we have analyzed published bacteriophage PRD1 reconstructions. We identified various structural details ranging from individual proteins to major complexes such as the whole capsid shell and more elaborate details of possible connections between membrane interfaces. This approach can also be a useful preprocessing tool for visualizing reconstructions.     

Normal electrocardiogram in guinea pig

For establishing normal mean values of the parameters of the electrocardiographic curve and their standard deviations 50 male guinea pigs were studied. The directions of temporary vectors of atrial (AP) and ventricular (AQRS) depolarization times, and ventricular repolarization time (AT) were determined, and the position of the heart was evaluated. In all animals limb leads I, II, III, aVR, aVL, aVF were used, and in 38 animals additionally the precordial leads V1, V2, V3, V4, V5, V6 were applied. The investigations were done by a non-invasive method with a specially designed plate making possible immobilization of the animals in supine position under general anaesthesia with urethane. In 10% of the animals abnormalities were detected in the ECG curve and these guinea pigs were eliminated from further analysis. The investigations showed that, after consideration given to the differences in the ECG curves in relation to man, guinea pigs might be used for preclinical cardiological studies.     

Construction of integrated genetic linkage maps by means of a new computer package: Join Map

A computerized procedure to contruct integrate genetic maps is presented. The computer program (J oin M ap ) can handle raw data from F₂s, backcrosses and recombinant inbred lines, as well as listed pair-wise recombination frequencies. The procedure is useful for combining linkage data that have been collected in different experiments; the result is a mathematical alignment of the distinct genetic maps. Data from single experiments can be dealt with as well. In view of the fast growing amount of linkage information for molecular markers, which is often being generated by different research groups, integrated maps provide useful information on the map position of genes and DNA markers.
The procedure performs a sequential build-up of the map and, at each step, a numerical search for the best fitting order of markers. Weighted least squares is used for the estimation of map distances.     

Radionuclide diagnosis of right ventricular myocardial infarction

The diagnostic capacities of 99mTc-pyrophosphate plane myocardial scintigraphy versus 99mTc-pyrophosphate single photon emission computed tomography (SPECT) were compared. Recording right precordial ECG leads showed that 26 patients had right ventricular myocardial infarction (MI)-typical changes as ST-segment evaluation, followed by abnormal Q wave. Plane scintigraphy indicated a characteristic inclusion of 99mTc-pyrophosphate into the right ventricular myocardium in 18.8% of the patients with acute lower MI and in one of 38 patients with acute MI of the anterior left ventricular wall. SPECT revealed a characteristic inclusion of 99mTc-pyrophosphate into the right ventricular myocardium much more frequently than did plane myocardial scintigraphy--in 34% of cases. Right ventricular myocardial inclusion of 99mTc-pyrophosphate was found in 50% of the patients with acute lower MI, including all 9 patients with positive 99mTc-pyrophosphate myocardial scintigraphy. Thus, the sensitivity of SPECT in the diagnosis of right ventricular MI is somewhat higher than that of precordial ECG and more than thrice higher than that of plane scintigraphy.     

A 2-cM genetic linkage map of human chromosome 7p that includes 47 loci.

A new high-resolution genetic linkage map for human chromosome 7p has been constructed. The map is composed of 47 loci (54 polymorphic systems), 19 of which are uniquely placed with odds of at least 1000:1. Four genes are represented, including glucokinase (GCK, ATP:D-hexose-6-phosphotransferase, EC 2.7.1.2) which was mapped via a (CA)n dinucleotide repeat polymorphism. The sex-average map measures 94.4 cM and the male and female maps measure 73.2 and 116.1 cM, respectively. We believe that the genetic map extends nearly the full length of the short arm of chromosome 7 since a centromere marker has been incorporated, and the most distal marker, D7S21, has been cytogenetically localized by in situ hybridization to 7p22-pter. The average marker spacing is 2 cM, and the largest interval between uniquely placed markers is 13 cM (sex-average map). Overall, female recombination was observed to be about 1.5 times that of males, and a statistically significant sex-specific recombination frequency was found for a single interval. The map is based on genotypic data gathered from 40 CEPH reference pedigrees and was constructed using the CRI-MAP program package. The map presented here represents a combined and substantially expanded dataset compared to previously published chromosome 7 maps, and it will serve as a "baseline" genetic map that should prove useful for future efforts to develop a 1-cM map and for construction of a contiguous clone-based physical map for this chromosome.     

Pyruvate stabilizes electrocardiographic and hemodynamic function in pigs recovering from cardiac arrest

Cardiac electromechanical dysfunction may compromise recovery of patients who are initially resuscitated from cardiac arrest, and effective treatments remain elusive. Pyruvate, a natural intermediary metabolite, energy substrate, and antioxidant, has been found to protect the heart from ischemia-reperfusion injury. This study tested the hypothesis that pyruvate-enriched resuscitation restores hemodynamic, metabolic, and electrolyte homeostasis following cardiac arrest. Forty-two Yorkshire swine underwent pacing-induced ventricular fibrillation and, after 6 min pre-intervention arrest, 4 min precordial compressions followed by transthoracic countershocks. After defibrillation and recovery of spontaneous circulation, the pigs were monitored for another 4 h. Sodium pyruvate or NaCl were infused i.v. (0.1 mmol·kg⁻¹·min⁻¹) throughout precordial compressions and the first 60 min recovery. In 8 of the 24 NaCl-infused swine, the first countershock converted ventricular fibrillation to pulseless electrical activity unresponsive to subsequent countershocks, but only 1 of 18 pyruvate-treated swine developed pulseless electrical activity (relative risk 0.17; 95% confidence interval 0.13–0.22). Pyruvate treatment also lowered the dosage of vasoconstrictor phenylephrine required to maintain systemic arterial pressure at 15–60 min recovery, hastened clearance of excess glucose, elevated arterial bicarbonate, and raised arterial pH; these statistically significant effects persisted up to 3 h after sodium pyruvate infusion, while infusion-induced hypernatremia subsided. These results demonstrate that pyruvate-enriched resuscitation achieves electrocardiographic and hemodynamic stability in swine during the initial recovery from cardiac arrest. Such metabolically based treatment may offer an effective strategy to support cardiac electromechanical recovery immediately after cardiac arrest.     

'DNA Strider': a 'C' program for the fast analysis of DNA and protein sequences on the Apple Macintosh family of computers

DNA Strider is a new integrated DNA and Protein sequence analysis program written with the C language for the Macintosh Plus, SE and II computers. It has been designed as an easy to learn and use program as well as a fast and efficient tool for the day-to-day sequence analysis work. The program consists of a multi-window sequence editor and of various DNA and Protein analysis functions. The editor may use 4 different types of sequences (DNA, degenerate DNA, RNA and one-letter coded protein) and can handle simultaneously 6 sequences of any type up to 32.5 kB each. Negative numbering of the bases is allowed for DNA sequences. All classical restriction and translation analysis functions are present and can be performed in any order on any open sequence or part of a sequence. The main feature of the program is that the same analysis function can be repeated several times on different sequences, thus generating multiple windows on the screen. Many graphic capabilities have been incorporated such as graphic restriction map, hydrophobicity profile and the CAI plot- codon adaptation index according to Sharp and Li. The restriction sites search uses a newly designed fast hexamer look-ahead algorithm. Typical runtime for the search of all sites with a library of 130 restriction endonucleases is 1 second per 10,000 bases. The circular graphic restriction map of the pBR322 plasmid can be therefore computed from its sequence and displayed on the Macintosh Plus screen within 2 seconds and its multiline restriction map obtained in a scrolling window within 5 seconds.     

氦氖激光对大鼠心肌超微结构、SOD和MDA影响的观察

为了解低强度氦氖激光对心肌细胞超微结构、超氧化物歧化酶（SOD）和丙二醛（MDA）的影响,采用2．87J／cm^2,7.17J/cm^2和28.66J/cm^2三种剂量氦氖激光照射大鼠心前区,电镜观察心肌超微结构,测定心肌组织SOD和MDA的含量。结果发现心肌线粒体有轻微损伤,心肌组织SOD含量在7．17J／cm^2剂量显著下降（P＜0．05）,而在28．66J／cm^2剂量显著升高（P＜0．05）,心肌组织MDA含量在7．17J／cm^2和28．66J／cm^2两种剂量下降有显著升高（P＜0．01）,在2．87J／cm^2剂量,心肌组织SOD和MDA含量均无显著变化（P＜0．05）。结果提示心肌SOD含量和脂质过氧化随不同的激光剂量而变化。     

Maps in birds: representational mechanisms and neural bases

The often extraordinary navigational behavior of birds is based in part on their ability to learn map-like representations of the heterogeneous distribution of environmental stimuli in space. Whether navigating small-scale laboratory environments or large-scale field environments, birds appear to be reliant on a directional framework, for example that provided by the sun, to learn how stimuli are distributed in space and to represent them as a map. The avian hippocampus plays a critical role in some aspects of map learning. Recent results from electrophysiological studies hint at the possibility that different aspects of space may be represented in the activity of different neuronal types in the avian hippocampus.     

Electrocardiographic Examinations in Dogs With Experimental Hepatitis Contagiosa Canis

Dogs with experimentally produced Hepatitis contagiosa canis were subjected to repeated electrocardiographic examinations during the course of the disease. Varying degrees of depression of the STJ and S-T segments and deviations of the T-wave were noted. Serum-electrolyte studies made during the illness showed a decrease of potassium, sodium, and chlorides which did not seem to be the cause of the observed electrocardiographic abnormalities. Circulatory disturbances and changes in the endothelial cells described elsewhere are considered to be the cause of a disturbance in the metabolism and the function of the myocardium with resulting depression of the STJ and S-T segments and deviations of the T-wave.     

Shape identification of electrocardiographic ST segment based on radial basis function neural network

The types of myocardial ischemia can be revealed by electrocardiographic (ECG) ST segment. Effective measurement and electrocardiographic analysis of ST as well as calculation of displacement and shape change of ST segment can help doctors diagnose coronary heart disease and myocardial ischemia, especially for asymptomatic myocardial ischemia. Therefore, it is a very important subject in clinical practice to measure and classify the ECG ST segment. In this paper, we introduce a computerized automatic identification method of the electrocardiographic ST segment shape with radial basis function neural network based on adaptive fuzzy system, which has a better effect than other methods. It helps to analyze the reason of the ST segment change and confirm the position of myocardial ischemia, and is useful for doctor diagnosis. Translated from Acta Biophysica Sinica, 2005, 21(6): 443–448 [译自: 生物物理学报]     

Automated error-tolerant macromolecular structure determination from multidimensional nuclear Overhauser enhancement spectra and chemical shift assignments: improved robustness and performance of the PASD algorithm

We report substantial improvements to the previously introduced automated NOE assignment and structure determination protocol known as PASD (Kuszewski et al. (2004) J Am Chem Soc 26:6258-6273). The improved protocol includes extensive analysis of input spectral data to create a low-resolution contact map of residues expected to be close in space. This map is used to obtain reasonable initial guesses of NOE assignment likelihoods which are refined during subsequent structure calculations. Information in the contact map about which residues are predicted to not be close in space is applied via conservative repulsive distance restraints which are used in early phases of the structure calculations. In comparison with the previous protocol, the new protocol requires significantly less computation time. We show results of running the new PASD protocol on six proteins and demonstrate that useful assignment and structural information is extracted on proteins of more than 220 residues. We show that useful assignment information can be obtained even in the case in which a unique structure cannot be determined.     

Local Explanations of Landscape Patterns: Can Analytical Approaches Approximate Simulation Models of Spatial Processes?

Research over the last 100 years has demonstrated the importance of space for ecological processes. Given this importance, it may seem natural to start investigations into broad-scale ecological processes with a comprehensive, broad-scale spatial map. Here we argue that it may sometimes be possible to answer important questions about spatial processes using crude spatial information obtained when a comprehensive map is not available. To present our argument, we first develop a simple simulation model for a perennial plant reproducing and dying on a landscape with different arrangements of suitable and unsuitable sites. We then develop a simple, analytical approximation to predict the fraction of suitable sites that are occupied by the simulated plants. The analytical approximation summarizes the spatial map by using a single parameter that gives the probability that a site adjacent to a suitable site is suitable. Comparing the predictions of both approaches highlights three points: (a) The role of the spatial environment in ecological processes may play out at the local scale. Therefore, studying the local-scale processes may provide insights into landscape patterns. (b) The predictions from the analytical approximation fail noticeably when suitable sites are rare and are distributed randomly (rather than clumped) on the map. In these situations, patches of interconnected suitable sites are very small, and populations within small patches may go extinct via demographic stochasticity. This illustrates how analytical approximations can be used to identify cases when local-scale spatial processes are not sufficient to understand the ecological consequences of space. (c) For many natural systems, constructing the appropriate environmental map needed to study ecological processes is difficult or impossible. However, summary characteristics such as those employed by the analytical approximation may be estimated directly in nature. Therefore, even in the absence of an explicitly spatial broad-scale map, it may be possible to study spatial processes by understanding which local-scale characteristics of space are important. Received 5 May 1997; accepted 31 July 1997.     

Molecular genetic linkage maps of mouse chromosomes 4 and 6.

We have generated a moderate resolution genetic map of mouse chromosomes 4 and 6 utilizing a (C57BL/6J x Mus spretus) F1 x Mus spretus backcross with RFLPs for 31 probes. The map for chromosome 4 covers 77 cM and details a large region of homology to human chromosome 1p. The map establishes the breakpoints in the mouse 4-human 1p region of homology to a 2-cM interval between Ifa and Jun in mouse and to the interval between JUN and ACADM in human. The map for mouse chromosome 6 spans a 65-cM region and contains a large region of homology to human 7q. These maps also provide chromosomal assignment and order for a number of previously unmapped probes. The maps should allow the rapid regional assignment of new markers to mouse chromosomes 4 and 6. In addition, knowledge of the gene order in mouse may prove useful in determining the gene order of the homologous regions in human.     

Seed quality QTLs identified in a molecular map of early maturing soybean

This study identified QTLs influencing seed quality characters in a cross of two early maturing soybean (Glycine max [L.] Merr.) cultivars (Ma.Belle and Proto) adapted to the short growing seasons of Central Europe. A molecular linkage map was constructed by using 113 SSR, 6 RAPD and 1 RFLP markers segregating in 82 individuals of an F₂ population. The map consists of 23 linkage groups and corresponds wellto previously published soybean maps. Using phenotypic data of the F₂-derived lines grown in five environments, four markers for protein content, three for oil content and eight for seed weight were identified. Four from fifteen seed quality QTL-regions identified in the present study were also found by other authors. Markers associated with seed weight QTLs were consistent across all environments and proved to have effects large enough to be useful in a marker-assisted breeding program, whereas protein and oil QTLs showed environmental interactions. Received: 9 October 2000 / Accepted: 26 February 2001