Search PubMed⌕ Search

Biomedical subjects

Z Sun

Publications and source records attributed to Z Sun.

At least 289 records · Page 16Linked to original sources
PubMed1992

Influence of medicinal herbs on phagocytosis by bovine neutrophils.

Twenty-six herbal preparations made from 24 medicinal herbs, categorized as antipyretics in Chinese materia medica, were tested in vitro to determine their effects upon phagocytosis of 32P-labelled Staphylococcus aureus by neutrophils isolated from bovine blood and milk. The percentage of phagocytosis was determined after incubating (1 hour at 37 degrees C) 1.25 x 10(7) neutrophils, 1 x 10(8) 32P-labelled S. aureus and 10% skimmed milk with herbal solutions. Concentrations of herbal preparations tested were 100%, 10% and 1% (v/v). When compared with PBSS (0.01 M phosphate buffered saline solution) controls, most of the herbs at high concentrations inhibited phagocytosis while at lower concentrations phagocytosis was increased. All 26 herbal preparations significantly increased blood neutrophil activity at their proper concentrations. The most active herbs in promoting blood neutrophil phagocytosis were observed for Herba verbenae, Flos chrysanthemi, Flos lonicerae, Radix sophorae flavescentis, Herba houttuyniae, Radix isatidis, Herba patriniae, Berberini sulfatis at the lowest concentration and for Folium hibisci at the high concentration with the increased percentage of more than 40.0% in comparison with PBSS control. Of the 19 herbal preparations tested with milk neutrophils, 18 herbs greatly increased phagocytosis at suitable concentrations. The most active preparations in stimulating milk neutrophil functions included Folium hibisci, Flos chrysanthemi, Radix bupleuri, Radix stellariae, Herba houttuyniae, Herba senecionis scandentis, Caulis lonicerae and Flos lonicerae which increased phagocytosis by over 35.0%.

Animals↗
PubMed1992

[Biochemical and immunological characterization of desmosomal proteins].

Desmosmoes were dissolved by incubation at 100 degrees C for 30 minutes in lysis buffer containing 9.5 M urea. SDS-PAGE revealed seven high molecular weight (> 67 kd) bands and some keratins. Seven of these were considered to be major bands. Bands 1 and 2 with M(r) values of 250 kd and 215 kd, called desmoplakins I and II. Polypeptide bands 3, 4a 4b, 5 and 6 had M(r) values of 165kd, 130kd, 115kd, 83kd and 75kd, respectively. 2-2.5mg of Desmoplakin I was obtained by a preparative electrophoresis; the purity reached 93.1%. The isoelectric pH range was between 6.8 and 7.2, and the amino acid compositions displayed a relatively high content of glycine. It was found that McAb Desmoplakin I recognized specifically the 250kd antigenic band by immunoblotting.

Amino Acids↗
PubMed1992

[The expression of oncogenes in the development of human brain].

Seven oncogenes (c-myc, L-myc, N-myc, v-erbB, c-fos, Ha-ras and mos) were used as the probe to detect the total RNA of every part (cerebellum, temporal folium, frontal folium and occipital folium) in human brain from 2 cases of 6 mon fetus and the total RNA in fetal development (4 mon, 5 mon, 6 mon, 7 mon, and newborn) of human brain tissue by RNA dot hybridization analysis. The results showed that most oncogenes were expressed at high level in cerebellum and occipital folium of 6 mon fetus and at low level in temporal folium; there was similar expression of c-myc, L-myc and N-myc in fetal development of human brain tissue, and the highest level was in the 5 mon fetal brain. There was no expression of erbB gene in normal human brain. The high level expression of Ha-ras and c-fos genes was in the middle and later stages of fetal development. These results suggested that c-myc, L-myc, N-myc, erbB, Ha-ras, c-fos and mos genes might play an important role in the fetal development of human brain.

Animals↗
PubMed1992

[The construction of rich genomic library of bovine Y chromosome].

According to the fundamentals of DNA renatured kinetics, we made a study in which genomic DNA from male cattle was completely digested with Sau 3A, while female DNA was sheared to an average size of 500 bp fragments. The Y derived DNA sequence rich library of bovine has been contracted with pUC19 plasmid as vector and JM109 as host bacteria by reassociation of male and female DNA. Male and female DNA probes, were used. The result of colony hybridization showed that out of 1000 recombinants analysed, 6 were found to be stronger signal with male probe. Analysis of Pvu' I digested DNA fragment revealed that most of the inserts were in the 90-300 bp.

Animals↗
PubMed1992

[Effects of insulin on expression of oncogenes in CWE mouse brain].

By RNA dot blot hybridization, we observed the expression of c-myc, c-fos, Ha-ras and erbB genes in normal brain of CWE mouse after the injection of insulin. Transcription of the c-myc and c-fos genes is greatly increased, which peaks approximately 2 h after insulin stimulation, decreases in 6 h and returns to the initial levels within 48 h. The alteration in Ha-ras transcription appears more complex; its expression decreases first but increases subsequently. We also detected the expression of erbB gene which decreases after the injection of insulin. The results suggest that c-myc, c-fos, Ha-ras and erbB might be directly involved in growth control. Their protein products might play a role in intracellular signal transduction.

Animals↗
PubMed1992

The effect of warm heart surgery on postoperative bleeding.

The effects of normothermic systemic perfusion (35 degrees to 37 degrees C; n = 73) were compared with those of moderately hypothermic systemic perfusion (25 degrees to 29 degrees C; n = 73) with respect to blood loss, transfusion requirements, and platelet levels in 146 patients undergoing isolated, primary coronary artery bypass grafting. In addition, most patients were given an antifibrinolytic medication during operation as follows: tranexamic acid (10 gm intravenously; n = 63), epsilon-aminocaproic acid (15 gm intravenously; n = 63), or no drug as a control. (n = 20). Normothermic patients tended to bleed less at 24 hours (warm, 864 +/- 42 ml and cold, 918 +/- 68 ml), but these differences were not statistically significant. Patients receiving either tranexamic acid or epsilon-aminocaproic acid, regardless of perfusion temperature, bled less after 6, 12, and 24 hours than did cold control patients (p less than 0.05). Warm control patients also bled less than did cold control patients after 6 or 12 hours (p less than 0.05), and neither drug further reduced blood loss in these patients. Circulating platelet levels were better preserved in patients receiving either tranexamic acid or epsilon-aminocaproic acid and in patients with warm perfusion and no drug than in cold control patients. Normothermic systemic perfusion, tranexamic acid, and epsilon-aminocaproic acid each reduced postoperative blood loss and preserved platelets.

Aminocaproic Acid↗
PubMed1992

[Effects of stimulation of renal afferent nerve on renal excretion of water, sodium and potassium].

The present study was designed to investigate the effect of stimulation of the renal afferent nerve (RAN) on renal excretory function and its mechanism. In pentobarbital-anesthetized, sino-aortic denervated and vagotomized (SAD+VD) cats, stimulation of the RAN caused a significant rise in arterial pressure. In the denervated kidney urine volume (Vu) and sodium excretion (UNa V) were greatly increased, no changes in potassium excretion (UK V) and glomerular filtration rate (GFR) were observed. In the innervated kidney, UNa V was greatly increased, but Vu, UK V and GFR were not different from those observed during the control period. When arterial pressure was held constant at the control level, stimulation of the RNA reduced the Vu, UK V of both the innervated and denervated kidneys and GFR in the innervated but not in the denervated kidney. Transection of spinal cord at C7 level did not abolish the changes in Vu, UNa V, and UK V in the innervated kidney, but completely eliminated the changes in the excretory function in the denervated kidney. These data suggest that when arterial pressure is controlled, stimulation of the RAN causes a decrease in Vu, UNa V, UK V in SAD+VD cats and that these responses in the innervated kidney can be performed at the spinal level.

Afferent Pathways↗
PubMed1991

Interim use of Jarvik-7 and Novacor artificial heart: blood rheology and transient ischemic attacks (TIA's).

The rheological properties of blood were studied in patients supported by both the Jarvik-7 total artificial heart (TAH) and Novacor left ventricular assist device (LVAD) as a bridge to cardiac transplantation. Both groups of patients had abnormalities in blood rheology which differed according to the type of device implanted as well as on the clinical state of the patient. The rheology of individual patients correlated well with their clinical status and outcome, with incidences of TIA's and/or stroke being accompanied by marked increases in relative blood viscosity, erythrocyte rigidity, fibrinogen concentration and platelet aggregation in varying combination. Observed abnormalities in blood rheology were also crucial to thrombus formation on artificial heart valves as well. Our results show that the therapeutic management of rheological parameters should prove to be a unique and clinically rewarding approach to these patients.

Adult↗
PubMed1991

[A study on the male DNA special restricted fragment of bovine].

Bkm, which is related to sexes, is a satellite DNA of the female snake. After the genomic DNA of bovine was digested by Pst I, it was hybridized with Bkm sequence probe (p184) and subcloned in the vector pUC19. Recombinants were identified by the colony in situ and Southern blot hybridization. When we determined genomic DNA of bovine using the male DNA fragment, it was observed that the pattern of hybridization was different because of different sexes. The results showed that we could identify the sex of bovine by Southern blot hybridization with recombinants of male DNA special restricted fragment of bovine origin.

Animals↗
PubMed1991

Design and compliance of HBV vaccination trial on newborns to prevent hepatocellular carcinoma and 5-year results of its pilot study.

A large-scale, controlled study of universal immunization of newborns against HBV infection has been conducted in the high incidence area of hepatocellular carcinoma, Qidong County of China. This area has a stable population, standardized cancer registration system, and an epidemiological base for measurements of liver cancer prevention by vaccine. Randomization was done on the community level. The vaccination and the control group each will consist of 38,000 children by the end of 1990. It is anticipated that the design will provide high statistical power to detect 50% reduction in the prevalence rate of chronic hepatitis among the vaccinees vs. the controls at 6 to 10 years of age, and 50% reduction in the incidence rate of hepatocellular carcinoma at 35 to 40 years of age. The vaccine used is Hep-B Vax, donated by Merck and Co. through WHO. The vaccine was administered at 0, 1, and 6 months after birth, the dosage of 5 or 2.5 micrograms in the pilot study as used before 1985 and of 5 micrograms dose level during the main study starting from January 1, 1985. About 85% of the cohorts have now entered the protocol. The vaccination coverage during 1984 to 1989 was 98.0% (35,064/35,789). Follow-up of the vaccinees and the age-matched controls at 5 years has exceeded 97%. The cumulative mortality in the vaccinated group up to 1988 was 1.29% (354/27,450). No single death nor serious adverse reaction was found that was associated with vaccination. The use of HBV vaccine at a reduced dose was especially important for the developing countries at the present time in order to achieve widespread immunization. Five-year results of the pilot study of this vaccination project showed that significant protection against HBV infection was achieved with the 5 or 2.5 micrograms per dose regimen plus a booster of 5 micrograms given at 3.5 to 4 years of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Hepatocellular↗
PubMed1991

[Effect of (-)-stepholidine on blood pressure and alpha-adrenoceptor agonists-, KCl- and CaCl2-evoked contractions of aortic strips].

Iv (-)-SPD lowered the blood pressure in anesthetized rat, the ED50 value was 5.1 +/- 2.5 mg.kg-1. In the experiments of rat and rabbit aortic strips, (-)-SPD 0.3-100.0 mumol.L-1 inhibited the contraction initiated by clonidine (alpha 2) and phenylephrine (alpha 1) and shifted the dose-response curve to the right parallely without change in maximum response. The inhibitory ratio of (-)-SPD acting on alpha 2/alpha 1 adrenergic receptors was about 7.2, and (-)-SPD thus was predominant inhibition on alpha 2 adrenergic receptors. In the experiment of aortic strips from reserpinized rabbits, the inhibition of (-)-SPD on contraction evoked by clonidine was diminished markedly. The results suggest that (-)-SPD stimulated mainly the alpha 2-adrenergic receptors of presynaptic nerve endings. Moreover (-)-SPD 1 mumol.L-1 inhibited the release of intracellular Ca2+ initiated by NE. (-)-SPD 3-30 mumol.L-1 blocked the voltage-dependent Ca2+ channel.

Animals↗
PubMed1991

[Isolation of desmosomes: a marker for epithelial tumors].

A simple method is reported for the isolation of desmosomes. The fresh noncornified layers of cow nose epidermis were immersed in 0.1 mol/L citric acid-sodium citrate buffer (pH 2.3, containing 0.5 mmol/L PMSF), and then treated with homogenization and discontinuous sucrose density gradient centrifugation. Desmosomes were located at the 50-56% sucrose interface. Electron microscopy revealed that the characteristic desmosome structure was well preserved, and that a few intermediate filament bundles attached to desmosome plaque were removed by the solubilizing action of the buffer. Approximate 100 mg desmosomes (dry weight) were got from 20g wet noncornified layers of epidermic tissue.

Biomarkers, Tumor↗
PubMed1991

[Immunodiagnosis of ovarian cancer].

Ovarian tumor associated antigen was isolated from human serous cystadenocarcinomas of ovary and purified by using affinity chromatography columns coupled to anti-normal female serum and anti-normal ovarian tissue gamma globulin. Antiserum was prepared from New Zealand white rabbits. The antiserum was absorbed with normal female serum and extracts of normal ovarian tissue thoroughly. The absorbed antiserum was appraised by immunodiffusion, immunoelectrophoresis and counter-immunoelectrophoresis with intensifiers. The absorbed antiserum has a specific immune precipitin with extracts of ovarian tumor tissue. Counter-immunoelectrophoresis with intensifiers was used to detect the ovarian tumor associated antigen in the tissue and serum of various patients. Twenty-eight of 40 ovarian tumor extracts and 1 of 5 cervical carcinoma extracts showed the presence of the cancer antigen. 14/40 were positive in the sera of ovarian tumor patients and 6/10 positive in the sera of ovarian serous cystadenocarcinoma patients; 1/5 positive in the sera of cervical carcinoma patients and 2/10 positive in the sera of ovarian cysts patients. No positive result for the sera of normal females was noted. The specificity, sensitivity and accuracy of the method were 94.7%, 42.3% and 83.3%, respectively.

Adenocarcinoma↗
PubMed1990

Degradation of Native Starch Granules by Barley alpha-Glucosidases.

The initial hydrolysis of native (unboiled) starch granules in germinating cereal kernels is considered to be due to alpha-amylases. We report that barley (Hordeum vulgare L.) seed alpha-glucosidases (EC 3.2.1.20) can hydrolyze native starch granules isolated from barley kernels and can do so at rates comparable to those of the predominant alpha-amylase isozymes. Two alpha-glucosidase charge isoforms were used individually and in combination with purified barley alpha-amylases to study in vitro starch digestion. Dramatic synergism, as much as 10.7-fold, of native starch granule hydrolysis, as determined by reducing sugar production, occurred when high pl alpha-glucosidase was combined with either high or low pl alpha-amylase. Synergism was also found when low pl alpha-glucosidase was combined with alpha-amylases. Scanning electron micrographs revealed that starch granule degradation by alpha-amylases alone occurred specifically at the equatorial grooves of lenticular granules. Granules hydrolyzed by combinations of alpha-glucosidases and alpha-amylases exhibited larger and more numerous holes on granule surfaces than did those granules attacked by alpha-amylase alone. As the presence of alpha-glucosidases resulted in more areas being susceptible to hydrolysis, we propose that this synergism is due, in part, to the ability of the alpha-glucosidases to hydrolyze glucosidic bonds other than alpha-1,4- and alpha-1,6- that are present at the granule surface, thereby eliminating bonds which were barriers to hydrolysis by alpha-amylases. Since both alpha-glucosidase and alpha-amylase are synthesized in aleurone cells during germination and secreted to the endosperm, the synergism documented here may function in vivo as well as in vitro.

Journal Article↗
PubMed1990

[Synthesis of zinc chlorophyllin a and its preliminary clinical application].

A method for synthesis of zinc chlorophyllin a (I), a promising drug for clinical application, is presented. Taking silkworm faeces as a raw material. Chlorophyll was extracted with ethyl alcohol. After concentration the solid formed was dissolved in petroleum ether and the solution was subjected to column chromatography to separate pheophytin a and chlorophyll a. The products were dissolved in ethyl ether and the Mg in the products was stripped off with concentrated hydrochloric acid. The excess hydrochloric acid in the solution was neutralized with ammonia solution and the mixture was hydrolyzed with diluted hydrochloric acid to obtain pheophorbide a, then (I) was synthesized with pheophorbide a and zinc salt. The characteristics of (I) and pheophorbide a were checked by IR, UV and elemental analyses. All results of pheophorbide a coincided with those values reported in literature. The acute toxicity of (I) was tested in mice and the LD50 of (I) was 324 +/- 40 mg/kg. (I) has been applied in several hospitals for several months. It has been found that (I) has outstanding effects on burns and oral sepsis and that it increases the growth of granulation tissue and epithelium remarkably.

Animals↗
PubMed1990

[Ocular hypotensive action of l-stepholidine].

Ocular hypotension was made by iv 20% NaCl 2.5 ml/kg in rabbits. On this model, l-stepholidine (l-SPD) lowered intraocular pressure when administered topically to the eyes. The ocular hypotensive action of 0.5% l-SPD was weaker than that of 0.5% timolol, but stronger than that of 0.5% pilocarpine. The maximal actions of the 3 drugs were similar. There were no significant changes of pupil diameter and carbonic anhydrase activity after l-SPD administered, but which suppressed aqueous humor formation. As the ciliary process of the eye behaves much like the renal glomerulus, dopamine increases the glomerular blood flow and dopaminergic antagonist decreases it, the mechanism of l-SPD in lowering intraocular pressure may be related to the dopaminergic receptor blocking effect of it.

Animals↗