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X Ying

Publications and source records attributed to X Ying.

At least 37 records · Page 2Linked to original sources
PubMed1994

Diameters of juxtacapillary venules determined by oil-drop method in rat lung.

We report a new method for precise quantification of lung microvascular diameter. Isolated blood-perfused rat lungs (500-g Sprague-Dawley rats) at constant inflation pressure [alveolar pressure (PA)] and stopped blood flow were viewed by microscopy and video. Subpleural venules of the second and third postcapillary generations were microinjected with oil colored with Sudan Black. Vascular pressure (Pvas) was varied in steps, and at each step the horizontal diameter (DH) and the length of the oil-filled segment were determined by microcaliper measurements of the replayed video image. At PA = 5 cmH2O, a decrease in Pvas from 25 to 0 cmH2O decreased DH in the second-generation venules from 55 +/- 2 (SE) to 41 +/- 1 microns (n = 13) and in the third-generation venules from 96 +/- 6 to 73 +/- 6 microns (n = 6). The constant-volume oil-filled segment conformed to the cylinder formula in that decreases in DH correlated linearly with 1/ square root of length, thereby indicating that at all Pvas values venular geometry was constant and probably circular in cross section. The decrease in Pvas to -5 cmH2O did not further decrease DH. At Pvas = 10-25 cmH2O, an increase in PA to 15 cmH2O did not significantly increase DH, although the increase in PA did diminish the slope (compliance) of the DH-Pvas relationship in second- but not third-generation venules. We conclude that 1) lung expansion decreases compliance of juxtacapillary venules, 2) venules retain circular cross sections at Pvas between -5 and 25 cmH2O, and 3) venules are patent at subzero Pvas.

Animals↗
PubMed1994

Removal of albumin microinjected in rat lung perimicrovascular space.

We used a microinjection approach to assess hydraulic properties of lung perimicrovascular adventitia (interstitial cuff surrounding microvessels). Isolated blood-perfused rat lungs held at constant airway pressure were microscopically viewed to identify subpleural venules (20 microns diam). Venular adventitia were microinjected with 20 nl of fluorescent albumin (4 g/dl), and then adventitial fluorescence was quantified at the injection site by either photometery or imaging. Nonlinear decay of adventitial fluorescence indicated liquid flux from the injection site into normal interstitium. In some experiments, we determined that the adventitial fluorescence flowed longitudinally along the venule length and filled single lymphatics. The fluorescence decay at the injection site was best described by equations of convective but not diffusive transport. The decay time constant (time to 37% initial), which relates inversely to hydraulic conductivity, increased 10-fold above baseline on lung expansion with airway pressure from 5 to 15 cmH2O (P < 0.05). However, presence or absence of blood flow, increase in filtration pressure, and tissue edema were all without effect on the time constant. Our estimate of the lower limit of baseline adventitial hydraulic conductivity was 5 x 10(-6) ml.cm-2.s-1.cmH2O-1. We conclude that hydraulic conductivity of perimicrovascular adventitia is not augmented by edema but that it is decreased by lung expansion.

Albumins↗
PubMed1994

The antioxidant butylated hydroxytoluene prevents early cholesterol-induced microcirculatory changes in rabbits.

Microcirculation was studied during 10 wk in untreated rabbits (n = 13) and in rabbits treated with dietary addition of 1% cholesterol (n = 13), 1% cholesterol + 1% of the antioxidant BHT (butylated hydroxytoluene) (n = 11), or 1% BHT (n = 5). The studies were performed by direct intravital microscopic imaging of the left and right conjunctivae with the use of a stereo microscope and a high resolution television camera. Microvessel diameter, erythrocyte flow velocity, and microhemorheologic conditions were evaluated quantitatively via a computer-assisted digital image processing system. Significant and marked changes occurred in all the above variables as a consequence of cholesterol feeding. After 3 wk of feeding there was a dramatic decrease (approximately 30%) in blood flow velocity in arterioli of the third order (P < 0.0001), accompanied by aggregation of cells in 40-50% of the smaller conjunctival vessels (P < 0.0001). These changes were enhanced further during the following 7 wk of treatment. All the above changes in the microcirculation were markedly reduced by the addition of BHT treatment. The diameter of the above arterioli decreased in the purely cholesterol-fed group (P < 0.005), whereas this did not occur in the group fed both cholesterol and BHT. In rabbits fed BHT in the absence of cholesterol, there was no significant effect on any assessed microcirculatory variable. In conclusion, the results demonstrate that the antioxidant BHT prevented early cholesterol-induced microcirculatory changes. This prevention occurred in the absence of a reduction of blood lipid levels. The results provide strong support for the hypothesis that a considerable part of the effects on microcirculation in hypercholesterolemia may be due to cholesterol-induced oxidations and not to cholesterol itself. The results are discussed in relation to the previously demonstrated antiatherogenic effect of BHT and the possible use of antioxidants in the therapy and prophylaxis of atherosclerosis.

Animals↗
PubMed1993

Selection of acrosome-reacted human spermatozoa and their fusing ability by micro-injection into the perivitelline space of hamster eggs.

Previously we reported the selective binding of human acrosome-reacted spermatozoa to monoclonal antibody-coated paramagnetic beads. In the present paper, the fusing ability of spermatozoa that bound to the beads was estimated by micro-injecting them into the perivitelline space of hamster oocytes. Acrosome-reacted human spermatozoa were collected by monoclonal antibody-coated paramagnetic beads. Bead-bound spermatozoa were selected under a microscope and micro-injected into the perivitelline space of hamster oocytes. When the injection was begun 5 min after mixing spermatozoa with the beads, 6.6% of the injected spermatozoa fused with an oocyte. However, when the injection was begun 30 min after the mixing, no fusion occurred. Moreover, when spermatozoa were injected with the beads attached to their head, no fusion was observed. The fusing ability of spermatozoa thus prepared was compared with that of randomly chosen and injected spermatozoa. Using spermatozoa from 10 healthy volunteers, 22 independent experiments were performed. The overall fusion rate of injected, randomly selected spermatozoa was 2.8%, whilst that of bead-selected spermatozoa was 7.3%. Selection of spermatozoa by beads appeared to be beneficial to the fusion event.

Acrosome↗
PubMed1993

Effects of hyperoncotic albumin on endothelial barrier properties of rat lung.

We have determined the effect of concentrated albumin on lung endothelial hydraulic conductivity (Lp) by our split-drop technique. We anesthetized 39 rats (2% halothane and pentobarbital sodium, 30 mg/kg ip; Sprague-Dawley, 500 g), then isolated and blood perfused their lungs. At constant inflation pressure (5 cmH2O) and stopped blood flow, we viewed subpleural venules (diameter, 20 microns) by microscopy and video. By micropuncture, we first microinfused a venule for 6 min with albumin that was either isoncotic (4 g/dl) or hyperoncotic (6 g/dl) with respect to rat plasma. In the same venule we then injected and split an oil drop with 4 g/dl albumin. From the rates of movement of the split oil drop at different vascular pressures, we determined Lp for 4 g/dl albumin. In venules that were previously microinfused for 6 min with 4 g/dl albumin, Lp for 4 g/dl albumin did not differ from that of noninfused controls (5.4 +/- 0.8 x 10(-7) ml.cm-2.s-1.cmH2O-1). However, after a similar microinfusion of 6 g/dl albumin, the Lp immediately increased more than two times above baseline (P < 0.01) but returned to baseline after 15 min. Lp for 4 g/dl albumin was not affected by hyperoncotic preinfusions of either neutral dextran or immunoglobulin G. We conclude that concentrated albumin caused a reversible increase of the lung endothelial barrier conductivity.

Animals↗
PubMed1993

Characterization of capacitation inhibitory protein from rabbit seminal plasma: homology with human annexins.

A protein was purified from rabbit seminal plasma using preparative acrylamide disc electrophoresis, ammonium sulfate precipitation and gel filtration. The protein inhibited the in vitro fertilization of mouse ova inseminated with epididymal sperm and with capacitated sperm. The inhibition was not observed, however, when only ova were exposed to the protein prior to mixing with sperm. The partial protein sequence analysis revealed the strong homology of the rabbit fertilization inhibitory protein to human annexin V.

Amino Acid Sequence↗
PubMed1992

Collection of acrosome-reacted human sperm using monoclonal antibody-coated paramagnetic beads.

A monoclonal antibody (MAb) against human acrosome-reacted sperm was attached to paramagnetic polystyrene beads. Human sperm prepared by the swim-up method were 1) incubated in m-BWW, 2) incubated and ionophore treated, or 3) incubated with 5% seminal fluid. After treatment, sperm were mixed with the beads and incubated for 1 hr. Variously treated sperm showed different binding abilities to the beads. Sperm bound to the beads were collected by a magnet and subjected to triple staining. Most of the collected sperm were acrosome reacted. The results suggested that the beads can be used to estimate the acrosomal status of sperm, and that the use of antibody-coated paramagnetic beads provides a convenient way of collecting acrosome-reacted sperm. The acrosomal status detected by the beads was also compared with the ability of sperm to fuse with zona-free hamster eggs. It was found that greater bead-binding ability correlated with more sperm fusing with zona-free hamster eggs.

Acrosome↗
PubMed1992

Increase of migration of cultured endothelial cells by angiotensin-converting enzyme inhibitor derived from tuna muscle.

The influence of angiotensin-converting enzyme (ACE) inhibitory octapeptide derived from tuna muscle (tuna AI) on the bovine aorta endothelial cell (BAEC) migration was investigated, as compared with captopril. BAEC migration was quantitated 6 d after release from contact inhibition by a teflon fence assay. The culture grown in the presence of tuna AI (1 and 10 microM) clearly exhibited an increase in migration, compared with the control. The media collected from tuna AI (1 and 10 microM)-stimulated BAECs significantly exhibited the interleukin (IL) -1 activity that was detected by the thymocyte costimulation assay with phytohemagglutinin. Although tuna AI was a weaker ACE inhibitor than captopril, the increasing effect of tuna AI on the migration and the IL-1 generation in BAECs was slightly greater than that of captopril. In quiescent BAECs, tuna AI (1 microM) apparently induced c-myc and platelet derived growth factor (PDGF) A-chain messenger ribonucleic acid (mRNA) expressions within 30 min, which persisted for 6 h. In contrast, captopril induced a very low expression of c-myc mRNA, and had no relation to PDGF A-chain mRNA expression. These results suggest that the increase of BAEC migration by tuna AI, unlike captopril, is likely related to the induction or activation of IL-1, and c-myc and PDGF mRNAs, in addition to the inhibition of the conversion of endogenous angiotensin I to angiotensin II.

Amino Acid Sequence↗
PubMed1992

Homology of an acrosome-reacted sperm-specific antigen to CD46.

MH61 is an acrosome-reacted sperm-specific monoclonal antibody. The antibody-coated beads effectively analyze the acrosomal status of human sperm. However, the nature of the antigen was not known. The antigen was purified by immunoprecipitation and SDS-PAGE followed by blotting on PVDF paper. The N-terminal sequence of the antigen was analyzed by an automated protein sequencer. An exactly matching sequence was found in CD46, that is also known as a membrane cofactor protein.

Acrosome↗
PubMed1991

A study on the catalytic performance of lipase in reverse micelles.

The hydrolysis of olive oil catalyzed by Candida rugosa lipase solubilized in "H2O/AOT/isooctane" reverse micellar solution has been studied. The optimal conditions observed for lipase in reverse micelles were t = 25 degrees C, pH = 7.9, and R = [H2O]/[AOT] = 10. Lipase in reverse micelles is found to be quite stable. For example, after being incubated at 33 degrees C for 12 hours in AOT/isooctane with R = 5.4, the residual activity of lipase remains as high as 89%. No inhibition was observed even though the substrate concentration was increased up to 50% (v/v), and it was inhibited slightly when 40 mM Cu2+, Co2+ or Mn2+ ions were in the water pools.

Candida↗