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GABAergic and glutamatergic synaptic input to identified granule cells in salamander olfactory bulb.

1. Whole-cell patch clamp recording techniques were applied to granule cells in an in vitro salamander olfactory bulb preparation to study their morphology, membrane properties and pharmacology of postsynaptic responses to electrical stimulation of either the olfactory nerve (ON) or medial olfactory tract (MOT). Optical recordings of the same preparations stained with the voltage-sensitive dye RH414 were also made. 2. Anatomical reconstructions of biocytin-filled granule cells showed that they extend widespread spine-bearing dendrites and an axon-like process that branched within the external plexiform layer. 3. ON or MOT stimulation evoked a long-lasting depolarization, usually generating only a single action potential, in granule cells studied under standard recording conditions. Bath application of bicuculline methiodide (BMI, a GABAA receptor antagonist, 20 or 25 microM) enhanced the spontaneous and electrically evoked excitatory drive to granule cells. 4. The electrically evoked synaptic responses consisted of both excitatory and inhibitory synaptic inputs. Using symmetrical Cl- conditions inside and outside the cell to enhance Cl- currents, spontaneous and electrically driven BMI-sensitive inhibitory postsynaptic currents (IPSCs) were revealed, indicating that granule cells receive GABAergic synaptic input. 5. Bath application of GABA (250 microM to 1 mM) shunted and hyperpolarized granule cells as observed directly from whole-cell recordings and indirectly from cell-attached patch single channel recordings. 6. Bath application of the glutamate receptor antagonists 6-cyano-2,3-dihydroxy-7-nitroquinoxaline (CNQX, 10 microM) and/or DL-2-amino-5-phosphonopentanoic acid (DL-AP5, 100 microM) showed that granule cell dendrodendritic EPSPs are shaped by both non-NMDA and NMDA receptors. 7. The time course and pharmacological sensitivity of both single granule cell responses and ensemble responses recorded optically in the deeper layers of the bulb correlated well. 8. It is concluded that salamander granule cells integrate several types of synaptic input, may have both dendritic and axonal output, and play a major role in generating voltage-sensitive dye signals in the olfactory bulb.

Afferent Pathways↗

Role for radA/sms in recombination intermediate processing in Escherichia coli.

RadA/Sms is a highly conserved eubacterial protein that shares sequence similarity with both RecA strand transferase and Lon protease. We examined mutations in the radA/sms gene of Escherichia coli for effects on conjugational recombination and sensitivity to DNA-damaging agents, including UV irradiation, methyl methanesulfonate (MMS), mitomycin C, phleomycin, hydrogen peroxide, and hydroxyurea (HU). Null mutants of radA were modestly sensitive to the DNA-methylating agent MMS and to the DNA strand breakage agent phleomycin, with conjugational recombination decreased two- to threefold. We combined a radA mutation with other mutations in recombination genes, including recA, recB, recG, recJ, recQ, ruvA, and ruvC. A radA mutation was strongly synergistic with the recG Holliday junction helicase mutation, producing profound sensitivity to all DNA-damaging agents tested. Lesser synergy was noted between a mutation in radA and recJ, recQ, ruvA, ruvC, and recA for sensitivity to various genotoxins. For survival after peroxide and HU exposure, a radA mutation surprisingly suppressed the sensitivity of recA and recB mutants, suggesting that RadA may convert some forms of damage into lethal intermediates in the absence of these functions. Loss of radA enhanced the conjugational recombination deficiency conferred by mutations in Holliday junction-processing function genes, recG, ruvA, and ruvC. A radA recG ruv triple mutant had severe recombinational defects, to the low level exhibited by recA mutants. These results establish a role for RadA/Sms in recombination and recombinational repair, most likely involving the stabilization or processing of branched DNA molecules or blocked replication forks because of its genetic redundancy with RecG and RuvABC.

ATP-Dependent Proteases↗

Control of carbohydrate processing: increased beta-1,6 branching in N-linked carbohydrates of Lec9 CHO mutants appears to arise from a defect in oligosaccharide-dolichol biosynthesis.

A correlation between increased beta-1,6 branching of N-linked carbohydrates and the ability of a cell to metastasize or to form a tumor has been observed in several experimental models. Lec9 Chinese hamster ovary (CHO) mutants exhibit a drastic reduction in tumorigenicity in nude mice, and this phenotype directly correlates with their ability to attach an increased proportion of beta-1,6-branched carbohydrates to the G glycoprotein of vesicular stomatitis virus (J. Ripka, S. Shin, and P. Stanley, Mol. Cell. Biol. 6:1268-1275, 1986). In this paper we provide evidence that cellular carbohydrates from Lec9 cells also contain an increased proportion of beta-1,6-branched carbohydrates, although they do not possess significantly increased activity of the beta-1,6 branching enzyme (GlcNAc-transferase V). Biosynthetic labeling experiments show that a substantial degree of underglycosylation occurs in Lec9 cells and that this affects several classes of glycoproteins. Lec9 cells synthesize ca. 40-fold less Glc3Man9GlcNAc2-P-P-lipid and ca. 2-fold less Man5GlcNAc2-P-P-lipid than parental cells do. In addition, Lec9 cells possess ca. fivefold less protein-bound oligosaccharide intermediates, and one major species is resistant to release by endo-beta-N-acetylglucosaminidase H (endo H). Membranes of Lec9 cells exhibit normal mannosylphosphoryldolichol synthase, glucosylphosphoryldolichol synthase, and N-acetylglucosaminylphosphate transferase activities in the presence of exogenous dolichyl phosphate. However, in the absence of exogenous dolichyl phosphate, mannosylphosphoryldolichol synthase and glucosylphosphoryldolichol synthase activities are reduced in membranes of Lec9 cells, indicating that membranes of Lec9 cells are deficient in lipid phosphate. This was confirmed by analysis of lipids labeled by [3H]mevalonate, which showed that Lec9 cells have less lipid phosphate than parental CHO cells. Mechanisms by which a defect in the synthesis of dolichol-oligosaccharides might alter the degree of beta-1,6 branching in N-linked carbohydrates are discussed.

Animals↗

The intrinsic organization of the nucleus lentiformis mesencephali magnocellularis: a light- and electron-microscopic examination.

The nucleus lentiformis mesencephali magnocellularis (nLMmc) is an essential part of the accessory optic nuclei and is responsible for stabilization of the horizontal eye movement. The morphology of this nucleus and its intrinsic structural connectivity were studied with Golgi, biotinylated dextran amine anterograde immunotracer and GABA immunostaining methods by light and electron microscopy. In the Golgi preparations neurons of large, medium-large, medium and small sizes were distinguished. The small neurons are GABA-immunopositive local circuit neurons, the others are proposed to be partly projection, partly local circuit neurons. The large and medium-large projection neurons are located in a tight topographical relationship observed in the Golgi preparations. The dendrites of the large and medium-large cells are also observed to be in close proximity with each other, and also with retinal fibre terminals. The morphological arrangement suggests that the retinal fibres make synaptic contacts with dendrites from both types of cell, and this is confirmed by the examination of retinal fibre terminals using electron microscopy. The optic fibre terminals establish synaptic contacts with small dendritic branches, dendritic processes and dendritic spines of large and medium-large neurons in the nLMmc. This arrangement allows the two types of nLMmc neuron access to very similar, if not identical, inputs, which may facilitate some of the different aspects of visual processing. Optic transmission by these cells may be modulated by the GABA-immunopositive terminals from various local circuit neurons, and very probably from GABAergic myelinated fibres as well, which may originate from the contralateral nLMmc and/or the visual Wulst.

Animals↗

Glucocorticoid-induced apoptosis of dendritic cells in the rat tracheal mucosa.

Dendritic cells are antigen-presenting cells that constitutively express high levels of major histocompatibility complex class II (Ia) antigen on their plasma membrane. Previous studies have shown that the number of dendritic cells in the rat airway mucosa decreases rapidly after glucocorticoid treatment. We sought to determine whether apoptosis contributes to this steroid-induced cell decrease. Dendritic cells in tracheal whole mounts were revealed by immunoperoxidase staining using the OX-6 (anti-Ia) monoclonal antibody. In untreated rats, a dense network of Ia-immunoreactive (Ia+) cells with highly branched cytoplasmic processes was observed just beneath the tracheal epithelium (1,405 +/- 140 cells/mm2 mucosa; mean +/- SEM, n = 6). In rats treated with dexamethasone (10 mg/kg, intraperitoneally), four distinct changes in dendritic cell morphology were evident 4 to 8 h after injection: (1) appearance of large Ia+ granules in cytoplasmic processes, (2) narrowing of cytoplasmic processes, (3) loss of Ia immunoreactivity from the cell surface, and (4) fragmentation of cells into small Ia+ bodies. These changes accompanied a 56% decrease in the number of Ia+ cells over 8 h. The contribution of apoptosis to this decrease in Ia+ cells was determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) of nucleosomal DNA fragments in histologic sections. The number of TUNEL+ bodies increased from a control value of 174 +/- 47 bodies/mm2 mucosa to 2,108 +/- 294 bodies/mm2 mucosa at 4 h and 936 +/- 343 bodies/ mm2 mucosa at 8 h (n = 4 rats per time point). The location of TUNEL+ bodies closely corresponded to that of Ia+ cells stained in adjacent histologic sections. We conclude that apoptosis contributes to the rapid decrease in airway dendritic cells after glucocorticoid treatment.

Animals↗

Binding of the baculovirus very late expression factor 1 (VLF-1) to different DNA structures.

BACKGROUND: Baculovirus genomes encode a gene called very late expression factor 1 (VLF-1) that is a member of the integrase (Int) family of proteins. In this report we describe the binding properties of purified Autographa californica multiple capsid nucleopolyhedrovirus (AcMNPV) VLF-1 to a number of different DNA structures including homologous regions. In addition, its enzymatic activity was examined. RESULTS: VLF-1 was expressed in a recombinant baculovirus as a fusion with both HA and HIS6 tags and its binding activity to different DNA structures was tested. No binding was evident to single and double strand structures, very low binding was observed to Y-forks, more binding was observed to three-way junctions, whereas cruciform structures showed high levels of binding. VLF-1 binding was affected by divalent cations; optimal binding to three-way junctions and cruciforms was 2 and 0 mM MgCl2, respectively. Homologous region (hr) sequences was also examined including oligomers designed to expose the hr palindrome as a hairpin, linear double strand, or H-shaped structure. Efficient binding was observed to the hairpin and H-shaped structure. No topoisomerase or endonuclease activity was detected. Sedimentation analysis indicated that *VLF-1 is present as a monomer. CONCLUSIONS: An HA- and HIS-tagged version of AcMNPV VLF-1 showed structure-dependent binding to DNA substrates with the highest binding affinity to cruciform DNA. These results are consistent with the involvement of VLF-1 in the processing of branched DNA molecules at the late stages of viral genome replication. We were unable to detect enzymatic activity associated with these complexes.

Journal Article↗

Interaction of nuclear receptors with the Wnt/beta-catenin/Tcf signaling axis: Wnt you like to know?

The cross-regulation of Wnt/beta-catenin/Tcf ligands, kinases, and transcription factors with members of the nuclear receptor (NR) family has emerged as a clinically and developmentally important area of endocrine cell biology. Interactions between these signaling pathways result in a diverse array of cellular effects including altered cellular adhesion, tissue morphogenesis, and oncogenesis. Analyses of NR interactions with canonical Wnt signaling reveal two broad themes: Wnt/beta-catenin modulation of NRs (theme I), and ligand-dependent NR inhibition of the Wnt/beta-catenin/Tcf cascade (theme II). Beta-catenin, a promiscuous Wnt signaling member, has been studied intensively in relation to the androgen receptor (AR). Beta-catenin acts as a coactivator of AR transcription and is also involved in co-trafficking, increasing cell proliferation, and prostate pathogenesis. T cell factor, a transcriptional mediator of beta-catenin and AR, engages in a dynamic reciprocity of nuclear beta-catenin, p300/CREB binding protein, and transcriptional initiation factor 2/GC receptor-interaction protein, thereby facilitating hormone-dependent coactivation and transrepression. Beta-catenin responds in an equally dynamic manner with other NRs, including the retinoic acid (RA) receptor (RAR), vitamin D receptor (VDR), glucocorticoid receptor (GR), progesterone receptor, thyroid receptor (TR), estrogen receptor (ER), and peroxisome proliferator-activated receptor (PPAR). The NR ligands, vitamin D(3), trans/cis RA, glucocorticoids, and thiazolidines, induce dramatic changes in the physiology of cells harboring high Wnt/beta-catenin/Tcf activity. Wnt signaling regulates, directly or indirectly, developmental processes such as ductal branching and adipogenesis, two processes dependent on NR function. Beta-catenin has been intensively studied in colorectal cancer; however, it is now evident that beta-catenin may be important in cancers of the breast, prostate, and thyroid. This review will focus on the cross-regulation of AR and Wnt/beta-catenin/Tcf but will also consider the dynamic manner in which RAR/RXR, GR, TR, VDR, ER, and PPAR modulate canonical Wnt signaling. Although many commonalities exist by which NRs interact with the Wnt/beta-catenin signaling pathway, striking cell line and tissue-specific differences require deciphering and application to endocrine pathology.

Animals↗

Morphological aspects of the human vestibular nerve.

A quantitative study was made of the number of fibers, their diameters, and distribution in the nerves innervating individual vestibular receptor organs of three human temporal bones. The specimens were obtained from autopsies conducted within 4 hours postmortem. The temporal bones containing the nerves were fixed in 3% glutaraldehyde and decalcified with EDTA until they were soft enough to allow dissection of the nerve branches to the individual receptors. The nerve branches were processed for osmium staining, embedded in plastic, and cut serially in 1-micron-thick sections for light-microscopic histologic evaluation of their fiber composition. Quantitative evaluation of nerve-fiber characteristics was made with the aid of a laboratory computer and programs for graphic representation and statistical analysis. In the nerves to the individual cristae the number of fibers ranged between 1416 and 2335. Fibers with diameters between 2.5 microns and 3 microns were the most numerous. The number of fibers decreased exponentially with increased size. The thickest fibers had diameters up to 11.5 microns. The distribution of fibers in the nerve of each crista was different for the central and intermediate areas of the crista than it was for the ends. Thin fibers with diameters less than 2.5 microns, which represented 36% of the population, projected to the ends of the receptor area. Thick fibers with diameters greater than 4.5 microns, which represented 8% of the fibers, were distributed relatively uniformly except for the extreme ends of the crista, where they were nearly absent. Fibers with intermediate diameters were distributed throughout the crista, although they were more concentrated at the ends. In the nerves to three maculae, the number of fibers ranged from 3744 to 5538. The percentage of fibers of each size, however, was similar to that in the cristae. The greater portion of fibers had diameters between 3.0 microns and 3.5 microns. Because of the anatomical configuration of the maculae, it was not possible to compare fiber diameters from one area to another. The composition and differential projection of fibers to the crista in the human labyrinth were similar to those found earlier in squirrel monkeys and bullfrogs. On the basis of these similarities in the pattern of innervation, it is suggested that the physiological properties in humans must be similar to those in animals.

Aged↗

Distribution and fate of macrophagic ameboid cells in the rat brain.

Following an intravenous injection of a fluorescent dye, primuline, into neonatal rats, the distribution of ameboid cells and their fate in the central nervous system were examined under incident fluorescence, light and electron microscopes. In the ameboid cells labeled with primuline, the ingested fluorogen spread throughout the cytoplasm, in which it appeared as a whitish yellow fluorescence. Such labeled cells displayed increased acid phosphatase (ACPase) activity. Combining primuline labeling with the ACPase reaction allowed for the identification of ameboid cells even after the transformation mentioned below. Ameboid cells were distributed throughout the white matter in neonatal rats, but were few in the gray matter. Particularly, they appeared as cell clusters in the corona radiata of the corpus callosum, the subependymal layer surrounding the ventricles, the fornical commissure, the internal and external capsules, the cerebellar peduncles and the medulla. Around 8 to 14 days after birth, the ameboid cells which had so far appeared spherical became gradually elongated with a few branched cytoplasmic processes, and scattered in the white matter. Thereafter, most primuline labeled cells transformed into cells with a dark nucleus and a thin cytoplasm including small phagosomes, i.e., into cells with features of microglia. However, a small number of ameboid cells underwent degeneration. The data indicate that the ameboid cells observed in the white matter during the postnatal period transform into microglia. Since other investigations suggest that the ameboid cells are derived from blood monocytes, microglia could initially come from monocytes.

Acid Phosphatase↗

Surface view of pericytes on the retinal capillary in rabbits revealed by scanning electron microscopy.

Retinal capillaries of the rabbit were treated with HCl and collagenase to visualize the pericytes attached to the stromal surface of the capillary walls under the scanning electron microscope. Two types of pericytes were distinguishable on the basis of shape and localization. One type (Type I) had a slightly bulged, fusiform cell body with a few, long, branching cytoplasmic processes, and these cells were scattered mainly in the region of the true capillary. The other type (Type II) possessed a rather flattened and polymorphic cell body from which radiated short irregular cytoplasmic processes, and these cells, which tended to overlap more or less, were present predominantly in the region of the pre- or postcapillary vessels in the capillary bed. The latter type cells were assumed to be precursors of the smooth muscle cells.

Animals↗

Protective effects of trimetazidine in transient spinal cord ischemia.

The neuroprotective effect of trimetazidine (TMZ) was tested prospectively in a rabbit spinal cord ischemia model. Ischemia was induced by clamping the aorta just distal to the left renal artery and proximal aortic bifurcation for 20 min. Twenty-five male New Zealand white rabbits were randomized as follows: TMZ group (n=100) receiving 3 mg/kg trimetazidine intravenously before the occlusion of the aorta; control group undergoing occlusion but receiving no pharmacologic intervention (n=10); sham-operation group (n=5) subjected to operative dissections without aortic occlusion. Physiological parameters and somatosensory evoked potentials (SEP) were monitored in animals before the ischemia, during the ischemia and in the 1st, 15th and 60th min of reperfusion. Neurologic status was assessed 24 and 48 h after the operation. The spinal cord, abdominal aorta, and its branches were processed for histopathologic examinations 48 h after the operation. At the end of the ischemic period, the average N1-P1 amplitude was reduced to 22% of the baseline in all ischemic animals. This was followed by a gradual return to 90+/-2% of the initial amplitude in the TMZ group and 81+/-2% in the control group (P<0.05) after 60 min of reperfusion. The average motor function score was significantly higher in the TMZ group than the control group (3.7+/-0.5 vs 3.1+/-0.6 at 24 and 3.5+/-0.7 vs 2.9+/-0.6 at 48 h; P<0.05). Histologic observations were clearly correlated with the neurologic findings. The results suggest that trimetazidine reduces spinal cord injury during thoracoabdominal aortic operations and may have therapeutic utility during high risk operations.

Animals↗

[Ethology and phylogeny of the family Belontiidae (Anabantoidei, pisces)].

1. The behavioural patterns of the following species of the family Belontiidae were qualitatively examined and compared with each other: Colisa lalia, C. fasciata, C. chuna, Trichogaster trichopterus, T. leeri, T. microlepis, Macropodu, opercularis, Pseudosphromenus (Macropodus) cupanus cupanus, Betta splendens, Trichopsis pumilus, T. vittatus vittatus, T. vittatus schalleri, Belontia signata and the hybrids Colisa fasciata X lalia. 2. Among other points the paper puts some emphasis on the description of the reproductive behaviour of the various species (nest building, mating, parental behaviour). In addition aspects of feeding and fighting behaviour are described. 3. The subfamilies established by Liem (1963) on the basis of osteological characteristics can also be substantiated ethologically. 4. Liem's conception of the phylogeny of Belontiidae is criticized. His system conceiving phylogeny as a process of branching off successively is contrasted with a phylogenetic fan. The subfamilies Belontiinae, Trichogasterinae and Macropodinae differentiated almost at the same time. 5. The genus of Macropodus has a very isolated position within the sub-family of Macropodinae. The remaining genera are on a higher level of development regarding their reproductive behaviour. As a result of the paper Pseudosphromenus (Macropodus) cupanus has to be eliminated from the genus of Macropodus.

Aggression↗

[Overexpression of STAT3 in COS7 cells causes prominent morphological changes].

Signal transducer and activator of transcription 3 (STAT3) plays a central role in mediating signals related to cell growth, differentiation, survival and movement. In this report, the results of immunocytochemistry and Western blot analysis showed that the active form of Stat3 protein existed in COS7 cells. The endogenous Stat3 protein could also induce the expression of m67-sequence-directed reporter genes. The transient transfection of Stat3 cDNA into COS7 cells increased Stat3 protein level and the expression of the reporter gene. The overexpression of Stat3 protein in COS7 cells caused prominent cell morphological changes. These cells had a much larger cell body, extended long processes with branches, lamellipodia and filopodia. These results suggest that Stat3 protein may play important roles in cell adhesion, migration and cytoskeleton reorganization.

Animals↗

[Observation on metacercariae of Paragonimus westermani by transmission electron microscopy].

The ultrastructure of metacercariae of Paragonimus westermani was observed by transmission electron microscopy. The worm is composed of integument, parenchyma, gut and excretory sac. The integument consists of tegument, muscular layer and tegumental cell. The tegument, a syncytium, includes tegumental membrane, tegumental cytoplasm, and basal plasma membrane. On the surface of the tegument, many finger-like processes with branches and spines can be readily identified. The spines projecting beyond the surface of the tegument are completely enclosed within the outer tegument membrane and the basal plasma membrane; in the transverse section, the spine shows a crystalline lattice structure. The tegumental cytoplasm consists of an electron dense granular matrix, in which two types of inclusion bodies, spherical and rod-like bodies may be recognised, both of them comprise a unit membrane and dense granular contents, the rod-like bodies are arranged along the edge of the spines. The tegument nuclei are located not within the surface syncytium but within sunken tegumental cells situated beneath the muscle layer, the tegumental cells contain a few cell organelles, and the two types of characteristic tegument inclusion bodies. The cells are joined to the tegument by one or more long, tortuous cytoplasmic tubules, responsible for the synthesis of the tegumental inclusion bodies, and that these inclusion bodies are translocated into the tegument by the cytoplasmic tubules. It suggests that the tegument of metacercaria is the main absorptive site of nutrients.

Animals↗

Malignant mesothelioma: cytologic diagnosis with histologic, immunohistochemical, and ultrastructural correlation.

The differential diagnoses of malignant mesothelioma in serous effusions include adenocarcinoma and reactive mesothelial cells. While several cytologic features are of predictive value in separating these entities, immunostaining and ultrastructural examination are important adjuncts that increase the diagnostic yield. Many of the cytomorphologic features can be correlated with immunohistochemical and ultrastructural findings. Most important among these is the ultrastructural demonstration of long, often branching microvillous processes in malignant mesothelial cells. Corresponding microvilli can be visualized by immunostaining for epithelial membrane antigen in both cell block preparations from effusions and biopsy specimens, allowing the identification of malignant mesothelioma. In addition, the circumferential distribution of these immunostained microvilli in cells dispersed in stromal connective tissue identifies them as malignant mesothelial cells, corresponding to the ultrastructural appearance of aberrant microvilli, which project through deficiencies in the basal lamina. These microvilli show interdigitation with stromal collagen fibers, a phenomena not observed in adenocarcinoma.

Adenocarcinoma↗

Perceptions of ethical problems by forensic psychiatrists.

A survey was undertaken of the opinions of two groups of forensic psychiatrists to determine their views regarding forensic ethical issues. Although AAPL has made significant strides for our profession by adopting ethical guidelines, some important issues have not yet been addressed, as revealed by our survey. Included were items heretofore considered too "controversial" for incorporation into guidelines, as well as items from the APA ethical framework. All APA items were evaluated as addressing ethical problems. The majority of respondents also viewed most of the "controversial" items as confronting relevant ethical problems, thereby suggesting their inclusion, in some form, in the profession's guidelines. They also appeared to favor retention of many traditional medical ethical values when functioning as a forensic psychiatrist. Clear selective discrimination existed among differing death penalty facets. Since AAPL at present does not wish to conduct its own ethics hearings, the AAPL guidelines as well as the items supported in this paper's survey would best be translated into a form consistent with the APA framework. In this way, AAPL's guidelines and also the new suggested items could readily be coordinated within the APA framework and could play a role in the APA local district branch enforcement process.

Capital Punishment↗

[Systolic and diastolic blood flow velocities in the left coronary artery before and following i.v. dipyridamole. Comparative measurements using a digital image processing in 2 unstenosed vessel branches].

The hemodynamic significance of coronary artery stenoses cannot be assessed by presently-used methods. Especially stenoses of small and moderate degree only reveal hemodynamic relevance during augmentation of coronary flow. It can be expected that the increase in flow is limited in a stenotic branch, compared with an unstenosed branch of the same vessel. The increase in coronary blood flow in two unstenosed branches of the same vessel, however, should be nearly identical. To prove this hypothesis, the relative increase in coronary flow was measured in two unstenosed branches of the left coronary artery by means of digital subtraction angiocardiography. Ten patients were examined before and after intravenous administration of 20 mg (on average 0.29 mg/kg body weight) dipyridamole. Dipyridamole resulted in an increase in the diameter of the left anterior descending branch (LAD) of 11% (p less than 0.005) and of the circumflex artery (RCx) of 13% (p less than 0.005). The increase in flow velocity during systole amounted to 49% in the LAD (p less than 0.001) and to 58% in the RCx (p less than 0.005); during diastole to 60% in the LAD (p less than 0.005) and 83% in the RCx (p less than 0.005). The increase in volume flow during systole amounted to 78% in the LAD (p less than 0.005) and to 89% in the RCx (p less than 0.005), during diastole to 84% in the LAD (p less than 0.005) and to 113% in the RCx (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗