Protein spot identification in two-dimensional electrophoresis gels can be supported by the comparison of gel images accessible in different World Wide Web two-dimensional electrophoresis (2-DE) gel protein databases. The comparison may be performed either by visual cross-matching between gel images or by automatic recognition of similar protein spot patterns. A prerequisite for the automatic point pattern matching approach is the detection of protein spots yielding the x(s),y(s) coordinates and integrated spot intensities i(s). For this purpose an algorithm is developed based on a combination of hierarchical watershed transformation and feature extraction methods. This approach reduces the strong over-segmentation of spot regions normally produced by watershed transformation. Measures for the ellipticity and curvature are determined as features of spot regions. The resulting spot lists containing x(s),y(s),i(s)-triplets are calculated for a source as well as for a target gel image accessible in 2-DE gel protein databases. After spot detection a matching procedure is applied. Both the matching of a local pattern vs. a full 2-DE gel image and the global matching between full images are discussed. Preset slope and length tolerances of pattern edges serve as matching criteria. The local matching algorithm relies on a data structure derived from the incremental Delaunay triangulation of a point set and a two-step hashing technique. For the incremental construction of triangles the spot intensities are considered in decreasing order. The algorithm needs neither landmarks nor an a priori image alignment. A graphical user interface for spot detection and gel matching is written in the Java programming language for the Internet. The software package called CAROL (http://gelmatching.inf.fu-berlin.de) is realized in a client-server architecture.

Algorithms↗

PubMedDate not supplied

Identification of human myocard proteins separated by two-dimensional electrophoresis.

N-Terminal sequencing, internal sequencing and amino acid analysis were used to identify twelve proteins of the human myocard two-dimensional gel electrophoresis (2-DE) pattern. Amino acid analysis was shown to be a powerful tool in addition to sequencing. The identification of a disease-associated N-terminally blocked protein by internal sequencing was not successful. The twelve identified proteins are the basis of a human myocard 2-DE database.

Amino Acid Sequence↗

PubMedDate not supplied

Towards design and comparison of World Wide Web-accessible myocardial two-dimensional gel electrophoresis protein databases.

In addition to the recently published HEART-2DPAGE--a myocardial World Wide Web-accessible 2-DE gel protein database--the usage and installation of software tools are described with regard to the hard- and software environments. Further, access to the HEART-2DPAGE from other two-dimensional electrophoresis (2-DE) databases using name or accession code of a protein is now available. Moreover, database images, published in the myocardial HSC-2DPAGE and HEART-2DPAGE databases are compared. Using the warping tool of the common image processing system Khoros the database images are matched and added in order to visualize the effects of warping. The application of such image processing tools is aimed at improving the comparability of protein spot patterns of different gel images available through the net.

Computer Communication Networks↗

PubMedDate not supplied

Electrophysiological properties of human coronary endothelial cells.

The electrophysiological properties of human coronary endothelial cells (HCEC) of macro- and microvascular origin were studied using the whole-cell configuration of the patch-clamp technique. The membrane potential of confluent HCEC (-41.9 +/- 3.9 mV (mean +/- SEM, n = 32) for macro- and -33.6 +/- 2.6 mV (n = 64) for microvascular cells, respectively) was less negative than the K+ equilibrium potential. Inward currents of isolated cells at potentials below the K+ equilibrium potential were blocked by external Ba2+ (1 mM), inactivated due to time- and voltage-dependent block caused by external Na+, and their amplitudes were enhanced by increasing extracellular [K+]; these currents were identified as inwardly rectifying K+ currents. Some isolated cells displayed outwardly directed K+ currents which were abolished after replacement of Cs+ for K+ on both sides of the membrane. Voltage-dependent Ca2+ currents could not be observed in isolated HCEC. Hyperpolarizations induced by vasoactive agonists have been observed in some endothelial cells from different species. In contrast, extracellularly applied ATP (adenosine-5'-triphosphate) and ADP (adenosine-5'-diphosphate) at micromolar concentrations depolarized confluent HCEC, whereas adenosine had no effect on resting potentials (RP), indicating that the nucleotide-induced depolarizations were mediated via P2- purinoceptors. These depolarizations occurred even after replacement of N-methyl-D-glucamine for extracellular Na+, indicating that Ca(2+)-influx was involved. There were no marked differences in the electrophysiological properties between cells of macro and microvascular origin.

Adenosine Triphosphate↗

PubMedDate not supplied

Using training needs analysis to implement change.

This article describes the application of a systematic approach to training needs analysis prior to a major change in practice. The authors suggest that such a systematic approach is a central component in the successful management of change.

Attitude to Computers↗

PubMedDate not supplied

Role of cytomegalovirus infection in the development of coronary artery disease in the transplanted heart.

In heart transplantation, accelerated graft arteriosclerosis leading to late postoperative graft failure is still an unsolved problem, and its pathogenesis is poorly understood. The existence of multiple underlying mechanisms has been discussed without conclusive results. In kidney transplantation, a negative influence of cytomegalovirus infection on long-term graft function and patient survival could be demonstrated. To evaluate the role of this infection on the incidence of coronary artery disease in the transplanted heart, we have analyzed the cytomegalovirus serostatus in 38 long-term survivors of orthotopic heart transplantation. In 14 patients (group A) graft arteriosclerosis was diagnosed by means of coronary angiography. In 24 patients (group B) the coronary vessels showed no pathologic findings. In 10 patients (71%) of group A serologic study showed evidence of cytomegalovirus infection, whereas only five patients (24%) of group B revealed cytomegalovirus infection. In two further patients of this group herpes zoster infection occurred (p less than 0.0001). Cytomegalovirus infection seems to be an important factor in the development of accelerated graft arteriosclerosis in the transplanted heart.

Adult↗

PubMedDate not supplied

[Angina pectoris and myocardial infarct with normal coronary arteries].

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Adult↗

PubMedDate not supplied

Alterations of left ventricular function and regional myocardial blood flow induced by nitrates in patients with coronary artery disease.

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Blood Pressure↗

PubMedDate not supplied

Coronary artery disease in patients with hearts from older donors: morphologic features and therapeutic implications.

Of 558 heart transplant recipients, 234 long-term survivors (more than 12 months) were studied by annual catheterization to evaluate the risk of postoperative coronary artery disease in hearts from older donors. No significant difference was found in graft function between hearts from younger and older donors (group I: n = 157, mean donor age 23 +/- 5 years, mean follow-up 45 +/- 22 months; group II: n = 77, mean donor age 43 +/- 5 years, mean follow-up 42 +/- 22 months) as indicated by left and right ventricular ejection fraction, pulmonary artery pressure, and pulmonary capillary wedge pressure. Two morphologic patterns of coronary artery disease were observed: a diffuse type of concentric narrowing of the arteries (type 1) and a focal type with proximal single-vessel stenosis (type 2). Type 1 occurred in eight patients (5%) in group I and in four patients in group II (5%) (p = not significant). Type 1 coronary artery disease led to graft failure in seven patients in group I and two patients in group II. Type 2 coronary artery disease occurred in seven patients (4%) in group I and in 14 (18%) in group II (p < 0.001). No death was related to graft failure in patients with type 2 coronary artery disease. Eight patients with type 2 coronary artery disease were successfully treated by percutaneous transluminal coronary angioplasty; one patient underwent coronary artery bypass grafting. Hearts from older donors provide normal graft function. The risk of diffuse coronary artery disease is not elevated in comparison to hearts from younger donors. The higher incidence of focal coronary artery disease suggests donor-transmitted disease that can successfully be treated by conventional therapy.

Actuarial Analysis↗