Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Microspectrophotometry”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed1975

Microspectrophotometric estimates of non-histone proteins in cell nuclei displaying differing degrees of chromatin condensation.

Nuclei isolated from mouse thymus, kidney, and liver were fixed in ethanol-acetic acetic acid; treated with dilute acid to extract histones; stained by three protein end-group procedures; and measured by scanning, integrating microspectrophotometry. Measurements were also made of nuclei isolated from the same organs and stained by the Feulgen procedure for DNA. Protein end-group procedures included pH 2.8 Biebrich scarlet (for basic groups), mercury orange (for sulfhydryl groups), and mercury orange after thioglycolate reduction (for the sum of sulfhydryl and disulfide groups). With the exception of the comparison between Feulgen-stained 2C liver and kidney nuclei, the integrated extinction values obtained for nuclei of a given organ differed significantly from the measurements of nuclei from other organs, regardless of the staining procedure. Furthermore, the integrated extinction values for 2C nuclei were highest in larger, more vesicular nuclei (from liver and kidney) and lowest in condensed thymocyte nuclei, except in the case of measurements of the disulfide content of the nuclei. In this instance, the values of integrated extinction were highest in condensed thymocyte nuclei, intermediate in kidney nuclei, and lowest in 2C liver nuclei. When 2C, 4C, and 8C liver nuclei were compared, the integrated extinction values of 4C nuclei were found to be approximately twice those of 2C nuclei whose disulfide and Feulgen values were, respectively, higher and lower than expected. The greater disulfide values and reduced Feulgen values obtained in thymocyte and 8C liver nuclei might be related to a greater degree of chromatin condensation in these nuclei, and therefore, to a reduction or selective restriction of their RNA transcriptional capacities.

Animals↗
PubMed1988

Moderate running exercise augments glycosaminoglycans and thickness of articular cartilage in the knee joint of young beagle dogs.

The local influences of physical exercise on thickness and glycosaminoglycan (GAG) content of canine articular cartilage were measured by microspectrophotometry of Safranin O- and periodic acid-Schiff (PAS)-stained tissue sections. Female Beagle dogs were housed in individual cages (bottom 0.9 x 1.2 m) and divided into runner (n = 6) and control (n = 8) groups. The training program started at the age of 15 weeks. During the subsequent 10 weeks, the dogs were accustomed to running on a treadmill inclined 15 degrees uphill. Thereafter, the dogs ran 1 h daily, 5 days a week, at a speed of 4 km/h for 15 weeks. At the age of 40 weeks, the dogs were killed, and the samples for histology were taken from 11 different anatomical locations of the right knee (stifle) joint. The thickness of the uncalcified cartilage increased 19-23% on the lateral condyle and patellar surface of the femur, whereas the enhancement was smaller in other parts of the trained cartilage. The calcified cartilage did not show thickness alterations. Total GAGs were augmented by 28% in the summits on the femoral condyles, more on the medial than lateral side. The increased GAGs appeared to be predominantly chondroitin sulphates and were localized in the intermediate, deep, and even in the calcified zones, whereas the superficial zone did not show changes. There was a concomitant increase of non-GAG oligosaccharides in the intermediate and deep zones, but not in the calcified cartilage.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Articular cartilage thickness and glycosaminoglycan distribution in the young canine knee joint after remobilization of the immobilized limb.

The recovery of articular cartilage from atrophy induced by joint immobilization was investigated in immature dogs. In a previous study, we showed that 11 weeks of immobilization of the knee (stifle) joint of young dogs reduced the concentration of articular cartilage glycosaminoglycans (GAGs) by 13-47%. In the present study, right hindlimbs from six female beagles were immobilized for 11 weeks, as in the previous study, and then were remobilized for 15 weeks. Cartilage from the knee joint was compared with cartilage from nonimmobilized knees of eight age-matched control beagles. Histological samples taken from 11 different locations of the knee joint were stained with safranin O, and microspectrophotometry was used to demonstrate distribution of GAGs in the tissue. After remobilization, GAG concentration was restored in the patellofemoral region and tibial condyles. On the summits of the femoral condyles, and especially at the periphery of the femoral condyles, GAG concentration remained 8-26% less than the control values. On the summits, the thickness of the uncalcified cartilage was as much as 15% less than in the age-matched controls. Consequently, the changes induced by unloading were reversible to a great extent, but a full restoration of articular cartilage was not obtained at all sites of the knee joint within the 15 weeks of remobilization. Immobilization of the skeletally immature joint therefore may affect the development of articular cartilage in such a way that very slow recovery or permanent alterations are induced.

Animals↗
PubMed1987

Evidence for differential DNA endoreplication during the development of a molluscan brain.

The DNA content of neurons in the cerebral ganglion of Achatina fulica was determined by the two-wavelength method of microspectrophotometry using Feulgen-stained sections. DNA measurements of mouse hepatocytes were used as a control of the methods. All sampled neurons with a nuclear diameter greater than 7 microns were polyploid. The shape of the frequency histogram of DNA contents is not compatible with an interpretation that assumes one or more simple duplications of the genome. It is suggested, instead, that the results are due to either the underreplication of some DNA sequences or the selective amplification of genes. Additional experiments using [3H]-thymidine autoradiography showed that the incidence of neuronal DNA synthesis is highest during the period of the animal's greatest growth and then declines rapidly near the onset of sexual maturity. The mesocerebrum incorporated greater amounts of [3H]-thymidine than the rest of the brain, whereas the procerebrum remained diploid throughout the course of the study.

Animals↗
PubMed1991

Hyperploid cells in the limb buds of rats and 5-azacytidine-induced digital deformities.

To clarify the mechanism underlying the digital teratogenesis of 5-azacytidine (5-AC), the DNA contents of mesenchymal cells were examined in the limb buds of the rat by microspectrophotometry. 5-AC induced hyperploid cells: 2.4% at 18 h after injection and 3.2% at 24 h. No hyperploid cells were noted 30 h after the treatment. Because posttreatment caffeine suppressed 5-AC-induced digital defects, the actions of caffeine on 5-AC-induced hyperploid cells were further studied; no hyperploid cells were detected at any sampling point. Caffeine suppressed hyperploid cells as well as digital defects. These results suggest that the causative factors of digital defects by 5-AC may involve hyperploid cells. However, in that there were too few hyperploid cells to cause the defects, further studies are required to clarify the nature of the action of 5-AC.

Abnormalities, Drug-Induced↗
PubMed1994

Expression of human alpha 1-antitrypsin in mouse after in vivo gene transfer to hepatocytes by small liposomes.

A plasmid (pTG7101) containing the full-length human alpha 1-antitrypsin gene was encapsulated in small liposomes and used for "in vivo" gene transfer to mouse hepatocytes, by i.v. injection (100 ng DNA/mouse and dose). The expression of human protein was evaluated by microspectrophotometry after human alpha 1-antitrypsin immunoperoxidase reaction on liver cryosections and the presence in mouse plasma of de novo synthesized protein was detected by ELISA analysis. Our results indicate that a single dose of encapsulated plasmid induces the expression of human alpha 1-antitrypsin in mouse hepatocytes and a large effect (70%) remains two weeks after treatment. However, no effect was observed when mice were treated with buffer or free plasmid (100 ng/mouse) plus an equivalent lipid dose of empty liposomes. In addition, whereas no additive effect was observed after repetitive treatment-doses, the partial hepatectomy three hours after a single treatment-dose, significantly increased the presence of human alpha 1-antitrypsin in mice plasma.

Animals↗
PubMed1995

Structure and oxygen affinity of crystalline desArg141 alpha human hemoglobin A in the T state.

The correlation of a protein structure determined crystallographically to its functional properties determined in solution can be an extremely complex problem due to potential differences of protein conformational flexibility in the two physical states. A more direct approach to the correlation of structure with function is to examine both the structure and the function of a protein in the same crystalline environment. In this paper, the structural and functional properties of T state desArg hemoglobin (human hemoglobin modified by removal of the alpha-chain COOH-terminal residue, Arg141 alpha) have been studied in the same crystal form by high resolution X-ray diffraction methods and by polarized absorption microspectrophotometry. Specifically, the crystal structure of deoxygenated desArg human hemoglobin has been refined at a 2.1 A resolution using crystals grown at low salt concentration from solutions of polyethylene glycol. The loss of Arg141 alpha and all of the salt bridges in which it participates is associated with subtle structural perturbations of the alpha-chains which include an increase in the conformational flexibility of both the NH2 and COOH-terminal peptides. Although the heme pockets appear unchanged and even the side-chain of Tyr140 is oriented nearly as in HbA, the functional characterization by microspectrophotometric measurements indicates that crystals of desArg hemoglobin bind oxygen with an affinity which is roughly 15-fold greater than that of crystals of human hemoglobin A. There is no alkaline Bohr effect or effect of chloride ions, but an acid Bohr effect is observed. The oxygen affinities measured along two principal axes of the crystals differ by 25%, indicating heterogeneity in the affinities of the oxygen binding sites. This finding and the measured Hill coefficient of unity suggest significant cooperativity in the binding of oxygen in these crystals. The origins of the observed heterogeneity and the implied cooperativity are unknown.

Arginine↗
PubMed1994

The effect of intracoronary nitroprusside on cyclic GMP and regional mechanics is altered in a canine model of left ventricular hypertrophy.

Nitroprusside can produce negative inotropy by activating cGMP. We hypothesized that in left ventricular hypertrophy produced by aortic valve plication (LVH), control of myocardial work and metabolism by cGMP production would be altered in response to nitroprusside. In anesthetized open chest preparations using 9 LVH and 12 control dogs, nitroprusside (4 micrograms/kg/min) was infused into the left anterior descending coronary artery. The circumflex (CFX) region served as an internal control. Segment force (miniature gauge) and length (sonomicrometer) were measured in both regions. Segment work was calculated as the integrated products of local force and segment shortening. Regional myocardial O2 consumption was calculated from blood flow measurements (radioactive microspheres) and regional O2 saturations (microspectrophotometry). Radioimmunoassay was used to determine regional cGMP levels. In control dogs, nitroprusside significantly reduced force in the treated region (from 10.3 +/- 0.8 to 7.9 +/- 0.9 g) and segment work (from 1889 +/- 296 to 1254 +/- 252 g.mm/min). In the LVH group, regional work, force, and shortening did not change. In the CFX regions of both groups, regional myocardial mechanics, as well as regional myocardial O2 consumption, were not altered during nitroprusside infusion. Cyclic GMP levels were elevated to a much greater extent in the LVH animals (from 3.26 +/- 0.60 to 15.23 +/- 4.65 pmole/g) than in the control animals (from 2.16 +/- 0.60 to 2.89 +/- 0.56 pmole/g). Thus, in contrast to control myocardium, significant increases in cGMP production during nitroprusside infusion failed to produce negative inotropy in LVH. These findings suggest an uncoupling between the second messenger and systems controlling muscle contraction.

Animals↗
PubMed1998

Myocardial effects of cyclic AMP phosphodiesterase inhibition are dampened in thyroxine-induced cardiac hypertrophy.

We tested the hypothesis that the increase in myocardial O2 consumption (MVO2) and myocardial wall thickening in response to milrinone would not be limited by thyroxine (T4)-induced (0.5 mg/kg for 16 days) cardiac hypertrophy. Anesthetized open-chest New Zealand white rabbits were divided into four groups: control vehicle (CV, n = 5), control milrinone (CM, n = 8), T4 vehicle (T4V, n = 7), and T4 milrinone (T4M, n = 9). Vehicle or milrinone (10(-3) M) were topically applied to the left ventricular epicardium for 15 min. Coronary blood flow (radioactive microspheres) and O2 extraction (microspectrophotometry) were used to determine O2 consumption. Cyclic AMP levels were determined by radioimmunoassay. T4 increased the heart weight to body weight ratio from 2.6 +/- 0.1 to 3.1 +/- 0.1 (g/kg). T4 rabbits had significantly higher baseline heart rates, blood pressures, and dP/dtmax and both subepicardial (EPI) and subendocardial (ENDO) blood flows. Topical application of milrinone did not have significant hemodynamic effects in either group. Baseline cyclic AMP levels (pmol/g) in the EPI and ENDO myocytes were comparable between control and T4 rabbits (CVEPI = 599 +/- 34, CVENDO = 532 +/- 26, T4VEPI = 656 +/- 42, T4VENDO = 657 +/- 17). Milrinone increased cyclic AMP in all groups although the increases were less in the T4 rabbits (CMEPI = 742 +/- 115, CMENDO = 698 +/- 101, T4MEPI = 742 +/- 103, T4MENDO = 690 +/- 55). Baseline MVO2 (ml O2/min/100 g) was significantly higher in T4 rabbits than controls (T4VEPI = 17.7 +/- 3.5 vs CVEPI = 8.5 +/- 1.5, T4VENDO = 17.2 +/- 3.2 vs CVENDO = 9.2 +/- 1.5). Significant increases in MVO2 were noted with the addition of milrinone in control (CMEPI = 14.8 +/- 3.0, CMENDO = 13.5 +/- 1.6) and T4 (T4MEPI = 25.5 +/- 3.4, T4MENDO = 22.0 +/- 3.3) rabbits; however, the percentage increase in MVO2 was significantly greater in controls (CEPI = 73%, CENDO = 47%) than T4 (T4,EPI = 44%, T4,ENDO = 28%). Thus, although the cyclic AMP phosphodiesterase activity was comparable between T4 rabbit hearts and controls, the metabolic effects and cyclic AMP effects of milrinone were dampened in this form of hypertrophy.

Animals↗
PubMed2000

Reduction in the level of cardiac cyclic GMP worsens contractile delay in myocardial stunning.

We tested the hypothesis that a reduction in the level of myocardial cyclic GMP would worsen the contractile delay associated with myocardial stunning. Two groups of 12 anesthetized open-chest New Zealand white rabbits were utilized. Myocardial stunning was produced by two 15-min occlusions of the left anterior descending coronary artery followed by 15 min of reperfusion. Either control vehicle (saline + 1% DMSO) or 1H-[1,2,4]oxadiazolo[4, 3-a]quinoxalin-1-one (ODQ 10(-4) M, a guanylate cyclase inhibitor) was topically applied to the left ventricular surface of the rabbit hearts. Left ventricular and aortic pressures along with wall thickness parameters were determined. Coronary blood flow (microspheres) and O(2) extraction (microspectrophotometry) were used to determine myocardial O(2) consumption. Myocardial stunning was observed in the control group through an increased delay in onset of wall thickening (46.2 +/- 7.3 vs 76.6 +/- 17.5 ms). There was no significant effect of stunning on the rate of wall thickening (21.8 +/- 9.5 vs 18.1 +/- 3.4 mm/s) or O(2) consumption (stun 4.6 +/- 0.6, control 4.8 +/- 0.4 ml O(2)/min/100 g). After treatment with ODQ 10(-4) M, both delay (43.9 +/- 9.6 vs 134.1 +/- 30.0 ms) and myocardial O(2) consumption (stun 5.9 +/- 0.6, control 5.9 +/- 0. 7) increased significantly compared to control. There was no significant change in the rate of wall thickening. We conclude that decreasing cyclic GMP worsens stunning by increasing delay in onset of wall thickening and increasing local O(2) costs in the stunned region.

Animals↗
PubMed1986

Control of the heterogeneity of O2 saturation in small myocardial veins.

There is a wide variability in the measured O2 saturations (SvO2) of small myocardial veins (20-100 microns). The purpose of the present study was to examine several factors that contributed to this variability. Studies were conducted on anesthetized open-chest dogs. The role of beta-adrenoceptors and flow in the control of the heterogeneity of SvO2 was assessed. The hearts were quick-frozen in liquid N2 and the SvO2 in the subepicardial and subendocardial (ENDO) regions of the left ventricule was determined by microspectrophotometry. Under control conditions, ENDO SvO2 averaged 35% with a variance of 337. The control variance was much more than that of the methodological errors. With propranolol or practolol, variance was reduced by about half, e.g. ENDO SvO2 variance was 145 with propranolol. This reduction in SvO2 variance could be prevented by isoproterenol. When flow is reduced by partial occlusion the SvO2 values were skewed toward lower saturations. When nitroglycerin is administered during this partial occlusion, the SvO2 distribution is restored toward normal. It can be concluded that some of the variability of SvO2 in the heart is control by beta 1-adrenoceptors. There also appears to be an inverse relationship between coronary blood flow and SvO2 heterogeneity. Further work is necessary to determine what other factors control the variability of SvO2.

Animals↗
PubMed1992

DNA ploidy of primary hepatocellular carcinoma and pulmonary metastases.

To better comprehend the differences in deoxyribonucleic acid (DNA) content between a primary hepatocellular carcinoma (HCC) and pulmonary metastatic nodules, tissue specimens taken at autopsy of 25 patients who had not received any drugs to treat the malignancy were examined using microspectrophotometry. The DNA distribution patterns were classified into Types I-III, and low (Types I and II) or high (Type III) ploidies, according to DNA distribution. Changes in the DNA content from high to low ploidies, namely DNA ploidy reduction from the primary lesion to pulmonary metastatic lesions, was evident in 9 of the 25 patients (36%), and changes from low to high were noted in 2 of the 25 patients (8%). The remaining 14 (56%) showed no evidence of changes in the DNA ploidy pattern. Reduction of DNA ploidy seen in HCC and its metastatic lesions in the lung may be one of the aspects of clonal evolution or selection mechanisms during the progression of tumor growth and metastasis.

Autopsy↗
PubMed1990

Photoreceptor-specific efficiencies of beta-carotene, zeaxanthin and lutein for photopigment formation deduced from receptor mutant Drosophila melanogaster.

Drosophila rearing media had only beta-carotene, zeaxanthin or lutein as precursors for photopigment chromophores. Zeaxanthin and lutein are potentially optimum sources of the 3-hydroxylated retinoids of visual and accessory photopigments. Mutants made the electroretinogram in white (w) eyes selective for compound eye photoreceptors R1-6, R7 and R8: R1-6 dominates w's electroretinogram; R7/8 generates w;ora's (ora = outer rhabdomeres absent); R8 generates w sev;- ora's (sev = sevenless). Microspectrophotometry revealed R1-6's visual pigment. In w, all 3 carotenoids yielded monotonic dose-responses for sensitivity or visual pigment. An ultraviolet sensitivity peak from R1-6's sensitizing pigment was present at high but not low doses. In w;ora, all 3 carotenoids gave similar spectra dominated by R7's high ultraviolet sensitivity. For w sev;ora, all spectra were the shape expected for R8, peaking around 510 nm. The sensitivity dose-response was at its ceiling except for low doses in w;ora and zero supplementation in w sev;ora. Hence, without R1-6, most of our dose range mediated maximal visual pigment formation. In Drosophila, beta-carotene, zeaxanthin and lutein mediate the formation of all major photopigments in R1-6, R7 and R8.

Animals↗
PubMed1977

Effects of the eye enucleation on the activity of monoamine oxidase and acetylcholinesterase in the superior colliculus of the rat.

Changes in the activity of monoamine oxidase (MAO) and acetylcholinesterase (AChE) following unilateral eye enucleation were measured for the superior colliculus (SC), lateral geniculate body (LGB), and nucleus suprachiasmaticus (NSC) in the rat by means of microspectrophotometry. The most conspicuous change of high significance was the decrease of MAO activity in the superficial strata of the SC contralateral to the enucleated eye. The other layers of SC, such as the stratum opticum, the intermediate strata, the deep strata and the central gray did not show significant postoperative changes in MAO acitivity. MAO activity of the LGB and the NSC was also not affected to a significant degree. The site of decrease of MAO activity in the superficial strata of the SC sould be degenerating optic nerve terminals. The strong AChE activity in the superficial strata may be derived from the horizontal cells. AChE activity in the SC showed only slight postoperative changes. The possible roles of the monoaminergic and cholinergic systems in the process of visual information are discussed.

Acetylcholinesterase↗
PubMed1975

A comparison of aldehyde fuchsin and alcian blue staining of neurosecretory material in Oncopeltus fasciatus.

The dynamics of the "A" cells of the parsintercerebralis of Oncopeltus fasciatus over the first eight days of adult life was studied by microspectrophotometry of sections stained either with aldehyde fuchsin or alcian blue 8 GX. The data show that the two stains differ in their selectivity as they record different events in the history of the cells. A hypothesis is proposed that the aldehyde fuchsin is more sensitive to the presence of a "carrier" protein in the cell, whereas alcian blue 8 GX is more sensitive to the presence of the "active principle" in the cell.

Alcian Blue↗
PubMed1978

Ultrastructural changes in the dermal chromatophore unit of Hyla arborea during color change.

The structural changes in the chromatophores of Hyla arborea related to changes in skin color were studied by electron microscopy and reflectance microspectrophotometry. During a change form a light to a darker green color, the melanosomes of the melanophores disperse and finally surround the iridophores and partly the xanthophores. The iridophores change from cup-shape to a cylindrical or conical shape with a simultaneous change in the orientation of the platelets from being parallel to the upper surface of the iridophores to being more irregular. The xanthophores change from lens-shape to plate-shape. The color change from green to grey seems always to go through a transitional black-green or dark olive green to dark grey. During this change the xanthophores migrate down between the iridophores, and in grey skins they are sometimes found beneath them. The pterinosomes gather in the periphery of the cell, while the carotenoid vesicles aggregate around the nucleus. The iridophores in grey skin are almost ball-shaped with concentric layers of platelets. A lighter grey color arises from a darker grey by an aggregation of melanosomes. The chromatophore values previously defined for Hyla cinerea are applicable in Hyla arborea, and the ultrastructural studies support the assumptions previously made to explain these values.

Animals↗
PubMed1980

Identification of the Balbiani ring 2 chromomere and determination of the content and compaction of its DNA.

The giänt puff Balbiani ring 2 (BR 2) in the salivary glands of Chironomus tentants is known to contain transcriptionally active 75S RNA genes. The corresponding chromosomal superstructure, the BR 2 chromomere, has been identified and characterized in the present study. It was demonstrated by cytological methods that BR 2 originates from the broad band IV-3B10, since all the bands except the 3B10 band could be detected as intact bands in the vicinity of BR 2. In situ hybridization of BR 2 RNA to squashed Malpighian tubule chromosomes lacking BR 2, showed that all or almost all the DNA sequences complementary to BR 2 RNA are located in the 3B10 band. The DNA amount in the 3B10 band, designated the Br 2 band, was measured in relation to the DNA content of the whole chromosome set by both direct and indirect microspectrophotometry of Feulgen-stained Malpighian tubule chromosomes. From a determination of the haploid DNA content in sperm cells (0.25 pg), the amount of DNA in at BR 2 chromomere could then be calculated to be 5.1 x 10-4 pg DNA or 470 kb DNA. A minimum value of the DNA compaction within the BR 2 chromomere was estimated to 380 from the B-form length of BR 2 DNA (160 mum) and the thickness of the BR 2 band (0.42 mum). Since there are only between 1 and 4 75S RNA genes, 37 kb in size, in a BR 2 chromomere, most of the BR 2 DNA must consist of DNA not coding for 75S RNA. The nature of this DNA is discussed in relation to the high average AT-content of Chironomus DNA. The orgnization of the chromosome fiber in the BR 2 chromomere is considered in relation to the gene activation process in the salivary glands, i.e. the formation of a 75S RNA transcription loop from a protion of the tightly packed chromosome fiber in the BR 2 chromomere.

Animals↗
PubMed1995

The effect of pancreatopeptidase E (elastase) on anastomotic intimal thickness in two types of vascular prosthesis.

To determine the effects of pancreatopeptidase E (elastase) on anastomotic intimal thickness in vascular prostheses, expanded polytetrafluoroethylene (ePTFE) and Dacron grafts were implanted in the infrarenal aortas of 28 adult mongrel dogs, divided into four groups of seven dogs each according to the type of graft used and whether or not elastase was given. Thus, group E received ePTFE grafts without elastase; group D received Dacron grafts without elastase; group E + Ela received ePTFE grafts with concomitant oral elastase, 8 mg/kg per day; and group D + Ela received Dacron grafts with elastase given at the same dosage as in group E + Ela. Each graft was harvested 4 months following surgery for histologic examination. It was clearly observed that elastase suppressed intimal growth at the proximal and distal anastomoses in the ePTFE grafts (P < 0.05), but not in the Dacron grafts. Furthermore, when we measured the smooth muscle cell percent extinction (%E) on microspectrophotometry in the intima within 2 mm of the proximal and distal anastomoses, it was found that elastase reduced intimal smooth muscle proliferation at the anastomosis of the ePTFE grafts, but not the Dacron grafts (P < 0.05). These data suggest that elastase suppresses intimal growth by inhibiting smooth muscle cell migration and proliferation in the vascular prostheses of low but not of high porosity.

Anastomosis, Surgical↗