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Biomedical subjects

Z Yang

Publications and source records attributed to Z Yang.

At least 901 records · Page 50Linked to original sources
PubMed1991

[An experimental study on the role of fluid replacement in the prevention of organ failure after burn injury].

44 dogs with 50% third degree burn were divided into 4 groups. Those without fluid replacement died within 12 postburn hours with complication of organ dysfunction; whereas those with immediate fluid replacement according to the Parkland formulae survived without definite organ dysfunction. But low-perfusion in the first 8-12 hours and some pathologic changes in the organs were seen. The results suggested that it is necessary to infuse fluid more rapidly in the first 2-3 hours. In group 3, most of the dogs with fluid replacement 6 hours after burn survived longer than the dogs without fluid replacement, but they were all complicated by severe organ dysfunction. This evidence that delayed inadequate resuscitation may be the primary factor affecting the development of early organ failure. In group 4, the dogs were given fluid replacement 6 hours after burn. The replacement was very rapid during the 7th and 8th hour. Both mortality and incidence of organ dysfunction in this group were decreased markedly. This result demonstrated that rapid infusion to replace loss of fluid within 2 hours was effective to treat shock and prevent progressive hypoxic organ damage.

Animals↗
PubMed1991

[Transplacental passage of vanadium after treatment with vanadium pentoxide in Wistar rat].

The passage of vanadium pentoxide across the placenta into the embryo/fetus was investigated by analyzing the vanadium content in embryo/fetus at various intervals between 1 h and 48 h after treatment of pregnant Wistar rats with single dose of the V2O5 (5mg/kg) on days 16-18 of gestation, at 4h after treatment of pregnant rats with single dose of V2O5 (5mg/kg) on day 12, and at 120 h after treatment of pregnant rats with dose of V2O5 0.33, 1.0, 3.0 mg/kg on days 6 through 15. The V concentration was determined by catalytic polarography. At after treatment on day 12, the V concentrations in maternal blood, placenta and embryos were elevated in comparison with those of the untreated group. At 4-48 h after treatment on days 16-18, the V concentrations in placenta and fetuses were elevated in comparison with those of the untreated group. The V concentration at 4 h after treatment in various tissues is the highest one among different time points. On days 16-18, 4 h after treatment, the V concentration in placenta was elevated in comparison with that on day 12 of gestation, but the V concentration in embryo/fetus was decreased. At 120 h after treatment on days 6-15, the V concentration in fetus is still high in comparison with that of the untreated group. The V content of fetus varied according to doses, suggesting that embryo/fetus accumulates vanadium. The results showed that vanadium can pass through the placental barrier and enter the embryo/fetus during the embryonal organogenesis in rat, but placenta accumulates vanadium, and the barrier action increases with placental maturity.

Animals↗
PubMed1991

Hemodynamic response to BMI model PIAB catheter.

Using the BMI model PIAB catheter designed and produced by our laboratory, we carried out serial animal experiments to evaluate its hemodynamic effects in goats. The animal experiments and comparison tests indicated that BAPDP = 24, PSP = 22; BAEDP = 8, EDP = 14; BAPSP = 20, PSP = 22. The various hemodynamic parameters of our PIAB catheter are equivalent to or better than those of imported products. But the price of our PIAB catheter is much lower than that of foreign products. It has been used in some hospitals, showing satisfactory results.

Animals↗
PubMed1991

[Influences of new synthetic drug vesnarinone on circulatory and respiratory function of dogs].

The purpose of this study was to investigate the influences of vesnarinone, newly synthesized in the School of Pharmacy, West China University of Medical Sciences in 1985, on the circulatory and respiratory functions of dogs. Eight dogs were anesthetized with 3% sodium pentobarbital. Vesnarinone (2 mg/kg), dimethyl sulphoxide (the solvent which was needed to prepare solution of OPC-8212), and 0.9% NaCl (normal control) was given separately according to the arrangement of Latin square. The ECG, blood flow, blood pressure and respiration were measured and recorded for 1-15 minutes. Vesnarinone increased the blood flow in the common carotid artery with no significant changes in blood pressure, heart rate, or respiration. These results suggest that OPC-8212 has positive inotropic effect but no effect on the heart rate in anesthetized dogs.

Animals↗
PubMed1991

[Studies on the mutagenicity of vesnarinone].

The mutagenicity of domestic Vesnarinone (OPC-8212) was studied by Ames test, micronucleus test of NIH mouse bone marrow and chromosome aberration assay in CHL cells. Negative results were obtained, which suggested that OPC-8212 did not induce prokaryotic cell gene mutation or chromosome damage both in vitro and in vivo.

Animals↗
PubMed1991

[A study on developmental toxicity of vanadium pentoxide in NIH mice].

There is no general agreement yet about the teratogenic effects or developmental toxicity of vanadium in animal studies. This is a report on developmental toxicity in NIH mice following injection of vanadium pentoxide (V2O5, 5 mg/kg body weight, i.p.) at different times of gestation (on days 1-5, 6-15, 7, 8, 9, 10, 11, 14-17 of gestation). No adverse effects of V2O5 on pre-implantation and implantation were noted, and neither were teratogenicity and premature birth. However, there was toxic effect on embryofetus. Increased frequency of resorption or fetal death on days 6-15, 7, 14-17 of gestation were observed. Delayed ossification of bones was noted on days 6-15, 8, 10, 14-17 of gestation. These results suggest that V2O5 may be a weak developmental toxicant but not a teratogen in NIH mice. In addition, this paper reports the developmental toxicity, especially teratogenicity of N, N'-methylene-bis (2-amino-1, 3, 4-thiadiazole) which was used as the positive control in NIH mice.

Animals↗
PubMed1991

[Distribution of vanadium in tissues of nonpregnant and pregnant Wistar rats].

This paper reports tissue distribution of vanadium in nonpregnant and pregnant Wistar rats. The experimental results showed that vanadium concentrations in nonpregnant rats were respectively from high to low: I. no treatment: ovary greater than uterus greater than kidney greater than lung greater than heart muscle greater than spleen greater than brain greater than liver greater than blood; II. 4h after single i.p. injection of V2O5 (5 mg/kg): kidney greater than ovary greater than liver greater than bone greater than uterus greater than lung greater than heart muscle greater than spleen greater than brain greater than blood. The results suggest that female genital organs are important organs in distribution of vanadium. The kidney is a main excretory organ. After 24h of treatment, a larger amount of vanadium in body has been excreted. Vanadium can pass through blood-brain barrier. Distribution of vanadium on gestation days 12 after 4h single i.p. injection of V2O5 (5 mg/kg) is: kidney greater than ovary greater than uterus greater than placenta greater than liver greater than fetus greater than bone greater than heart muscle greater than lung greater than brain greater than spleen greater than blood; on gestation days 16-18 after 4h single i.p. injection of V2O5 (5 mg/kg) is: kidney ovary greater than placenta greater than lung greater than bone greater than uterus greater than heart muscle greater than spleen greater than fetus greater than liver greater than brain greater than blood; after 24h (on gestation days 16-18) is: kidney greater than ovary greater than placenta greater than spleen greater than bone greater than lung greater than liver greater than fetus heart muscle greater than brain blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Antigenic analysis and identification of serotype for an arguable strain of Shigella].

A strain of Shigella, 51331, was isolated abroad in 1935, and stored in The Center for Medical Culture Collection, Beijing. Since the serotype of this strain was arguable in China. It was identified as Sh. flexneri var. X with antigenic analysis. As agglutinin absorption technic was used in preparing diagnostic factor serum, it appears that the culture of strain 51331 could be agglutinated by Shigella antiserum flexner type 3 (Sh. flexneri) made in China and England. The present author suggested that diagnostic serum for type 3 or Sh. flexneri should be checked up with the strain 51331 for type factor specific. Strain 51331 is, therefore, useful for purpose of identification when preparing diagnostic serum for Shigella.

Antigens, Bacterial↗
PubMed1991

Clinical and experimental observations on treatment of peptic ulcer with wei yang an (easing peptic-ulcer) capsule.

The therapeutic effects of peptic ulcer treated with cimetidine and Wei Yang An were compared clinically and experimentally by the double blind method. Results showed that the effects of the two are similar, but the long-term effect of Wei Yang An was better. Wei Yang An was also good for most cimetidine resistant ulcers, with few side effect. Animal experiment showed that Wei Yang An inhibited the ulcers.

Adult↗
PubMed1991

[Effect of prefrontal cortex stimulation on the activity of pain-related neurons in parafascicular nucleus of thalamus in rats].

The effects of PFC stimulation on spontaneous and evoked discharges of neurons of parafascicular nucleus of thalamus were observed in rats. The results show that after PFC stimulation spontaneous of 78.7% PEN (48/61) and evoked discharges on noxious stimulation of 76.6% PEN (46/60) were decreased; spontaneous discharges of 72% PIN (18/25) were increased; inhibition response on noxious stimulation of 70.8% PIN (17/24) were decreased; and spontaneous discharges of 66.7% CON (6/9) and evoked discharges on noxious stimulation of 55.6% CON (5/9) were decreased. The results suggest that PFC might have analgesia action which was accomplished by modulating electric activities of pain-related neurons of parafascicular nucleus in thalamus.

Animals↗
PubMed1990

Structural features of the cytoplasmic region of CD4 required for internalization.

CD4, the T cell surface antigen, is phosphorylated and internalized when T cells are activated or treated with a phorbol ester, PMA. The actual phosphorylation sites have been identified and the role of phosphorylation of each on CD4 internalization investigated. Seven different mutants, in each of which one, two or all three of the serine residues of the cytoplasmic region was modified to alanine(s) (CD4.SA mutants) and one mutant in which the whole amino acid sequence from Gln421 to the C-terminal Ile433 was changed (CD4.EP mutant) were constructed and used to determine the effect of phosphorylation on CD4 internalization. Ser408 was the most efficiently phosphorylated by PMA treatment, Ser415 next and Ser431 to a minor extent. The effect of mutation on internalization was well matched with the effect on extent of phosphorylation, i.e. Ser408 was the residue most important for internalization. However, complete inhibition of CD4 internalization was achieved only by mutating all three serine residues. Interestingly, the mutant CD4.EP in which Ser408 was present and phosphorylated was not measurably internalized, suggesting that phosphorylation of Ser408 induces CD4 internalization only when other structural features of the cytoplasmic domain remain intact. In addition, the data suggest the existence of an additional minor pathway for CD4 internalization which is phosphorylation independent.

Amino Acid Sequence↗
PubMed1990

Interferon gamma response region in the promoter of the human DPA gene.

The interferon gamma (IFN-gamma) response region of the human class II major histocompatibility complex gene, DPA, has been localized to a 52-base-pair (bp) DNA fragment in the proximal promotor at -107 to -55 bp after transfection into HeLa cells of a series of 5', 3', and gap deletion mutants linked to a reporter gene, human growth hormone, as well as of synthetic oligonucleotides fused to the heterologous promoter thymidine kinase. The 52-mer sequence contains the X and Y box elements conserved in all class II genes; their presence is indispensable for IFN-gamma inducibility. Furthermore, an additional 5 bp immediately 5' of the X box of the DPA gene are necessary and sufficient for IFN-gamma induction. This region may contain an IFN-gamma response element. A closely related sequence has also been found in the vicinity of the critical deletion sites of three other well-studied class II gene promoters, all of which require a much longer sequence 5' of the X box. A fourth element, the W element, located about 15 bp 5' of the X box in all class II genes, is clearly of little importance in IFN-gamma inducibility of the DPA gene.

Base Sequence↗
PubMed1990

Different mobilization of calcium in endothelin-1-induced contractions in human arteries and veins: effects of calcium antagonists.

We studied the role of extra- and intracellular Ca2+ in endothelin-1-induced contractions of the isolated human internal mammary artery and vein. Veins were more sensitive to the peptide than arteries (concentration shift:3.2-fold; n = 4-10, p less than 0.05). The Ca2+ antagonists darodipine, verapamil, and diltiazem (10(-7)-10(-6) M) did not prevent the response to endothelin-1 in both vessels. In contrast, darodipine (10(-8)-10(-6) M), added after the contraction had developed, partially reversed the response in the artery (26 +/- 7%) and particularly in the vein (67 +/- 5%; n = 4, p less than 0.005 compared to the artery). Removal of extracellular Ca2+ reduced the contractions to endothelin-1 (10(-8) M) in the artery (control: 89 +/- 4% of 100 mM KCl; Ca2(+)-free: 68 +/- 4% n = 4-6, p less than 0.01), but not in the vein except at low concentrations (10(-9) M) of the peptide. After removal of intracellular Ca2+ with caffeine in the artery, endothelin-1 still evoked a contraction (17 +/- 3%, n = 3; p less than 0.005 vs. control), while in the vein the response was abolished. Thus, mobilization of Ca2+ during endothelin-1-induced contractions differs in the human internal mammary artery and vein. In the artery, the contraction depends on extracellular Ca2+, intracellular caffeine-sensitive Ca2+ stores, and a caffeine-insensitive component, while in veins, mobilization of intracellular Ca2+ is most important. Ca2+ antagonists do not prevent, but partially reverse, endothelin-1-induced contractions indicating that voltage-operated Ca2+ channels do not initiate but contribute to the maintenance of the response.

Caffeine↗
PubMed1990

Interaction between endothelin-1 and endothelium-derived relaxing factor in human arteries and veins.

Endothelin-1 is a 21-amino acid endothelial vasoconstrictor peptide that may be the physiological antagonist of endothelium-derived relaxing factor (EDRF). Endothelin-1 (10(-11)-3 x 10(-7) M) evoked potent contractions of isolated internal mammary arteries, internal mammary veins, and saphenous veins, which were enhanced in internal mammary veins as compared with internal mammary arteries (concentration shift, 6.3-fold; p less than 0.05) but not in the saphenous veins. Endothelial removal augmented the response to the peptide (at 3 x 10(-7) M) in internal mammary arteries (p less than 0.05) but not in veins. In the artery, EDRF released by acetylcholine or bradykinin reversed endothelin-1-induced contractions; in saphenous veins, both agonists were much less effective compared with the artery and veins contracted with norepinephrine (p less than 0.005-0.01). This inhibition of endothelium-dependent relaxations in veins occurred at half-maximal contractions but was most prominent at maximal contractions to the peptide. Nitric oxide similarly inhibited contractions to endothelin-1 and norepinephrine in internal mammary arteries, whereas in veins that were contracted with endothelin-1 but not with norepinephrine, the relaxations were blunted (p less than 0.005). The nitric oxide donor SIN-1 and sodium nitroprusside induced complete relaxations of internal mammary arteries but were less effective in veins contracted with endothelin-1 (p less than 0.005). Thus, in normal human arteries, EDRF inhibits endothelin-1-induced contractions, whereas the peptide specifically attenuates the effects of EDRF and nitrovasodilators in veins. This may be important in pathological conditions associated with increased levels of endothelin-1 and in veins used as coronary bypass grafts.

Acetylcholine↗
PubMed1990

[Comparative study of Campylobacter pyloridis and Campylobacter jejuni under electron microscope].

Specimens were made by preparing the ultrathin sections after negative staining and ruthenium red staining. The specimens were observed under electron microscope. Results revealed that the shapes of Campylobacter pyloridis (Cp) and C. jejuni (Cj) were similar, but distinctive differences in their structures were observed. Cp had one to five sheathed flagella at one end with bulbous tips. Cj had only one unsheathed flagellum on each end without a bulbous tip. The cell body of Cp was longer than that of Cj. A layer of thick and dense delicate filament-like substance was attached to the surface of the cell body of Cp in the ultrathin sections with ruthenium red staining, in the case of Cj only a little of such a substance could be noted.

Campylobacter jejuni↗
PubMed1990

[The effect of China-made amrinone on myocardial infarction and arrhythmia in dogs].

Six dogs underwent 15 min left anterior descending (LAD) coronary artery occlusion (CAO) with 1 hour's reperfusion for 3 times. Fifteen min after CAO (control), CAO during amrinone (Amr), and CAO during isoprenaline, sigma ST (mV) and ST (mV) were 66 +/- 26 and 8 +/- 2.72 +/- 61 and 9 +/- 4.90 +/- 48 and 11 +/- 6 respectively, 24h after LAD CAO, dP/dt max (kPa/s) and HR (heart beats/min) were 483 +/- 93 and 211 +/- 36 respectively. Intravenous Amr by 1, 5, 3 and 6 mg/kg increased dP/dt max to 630 +/- 79, 583 +/- 116 and 500 +/- 148; HR to 223 +/- 44, 232 +/- 45 and 239 +/- 54; and also decreased SBP, DBP and LVEDP. Amr caused neither change in percentage of non-sinus beats, nor ventricular fibrillation. These results suggested that in myocardial infarction and arrhythmia, Amr could still be of positive inotropic effect. Amr worsened myocardial infarction in nonfailing heart, but it did not aggravated arrhythmia after myocardial infarction.

Amrinone↗
PubMed1990

Serotonin and the endothelium.

Serotonin has many and opposing effects in the cardiovascular system. The vascular endothelium importantly contributes as a modulator and mediator of the cardiovascular effects of serotonin. Endothelial cells contain the enzyme monoaminooxidase which inactivates serotonin. In addition, endothelial cells are a source of vasodilator substances such as endothelium-derived relaxing factor, the endogenous nitrovasodilator. Nitric oxide is continuously formed by the arterial endothelium to inhibit the effects of vasoconstrictor substances such as serotonin. Accordingly, removal of the endothelium enhances contractions induced by serotonin in most vascular preparations. In certain blood vessels, such as the porcine and canine coronary artery, serotonin stimulates the release of endothelium-derived nitric oxide. Endothelium-dependent relaxations to serotonin also occur in intramyocardial porcine coronary resistance arteries. In contrast to porcine and canine arteries, endothelium-dependent relaxations to serotonin have not been demonstrated in the human coronary and internal mammary artery. In the porcine coronary artery with regenerated endothelium and in that with atherosclerotic changes, the endothelium facilitates contractions to serotonin, suggesting that an endothelium-derived contracting factor is released. Since indomethacin prevents this endothelium-dependent facilitation of contractions to serotonin in atherosclerotic porcine coronary arteries, a cyclooxygenase product is likely involved. Similarly, in the aorta of spontaneously hypertensive rats, the endothelium facilitates the contractions to serotonin. Thus, the endothelium can importantly modulate the response to serotonin. While in normal arteries, the cells inhibit the vasoconstrictor effects of the monoamine, the endothelium facilitates its contractions in atherosclerotic and hypertensive blood vessels.

Animals↗