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Biomedical subjects

Y Ding

Publications and source records attributed to Y Ding.

At least 91 records · Page 5Linked to original sources
PubMed2001

Variations in cardiac diastolic function in hypertensive patients with different left ventricular geometric patterns.

To evaluate the alteration of cardiac function in hypertensive patients with different left ventricular geometric patterns. Echocardiography was used to study left ventricular geometry and cardiac diastolic function in 117 cases of essential hypertension, with 45 normal cases as controls. Echocardiographic date were used to calculated the left ventricular mass index (LVMI) and relative wall thickness (RWT), which values in turn were used to divide the subjects into four groups. The left atrial dimension of the group, with the exception of these hypertensives who showed normal geometry, was larger than that of the control group. The damage of peak of E velocity, peak of A velocity, E/A and the slope between the E and F points (E to F slope) were greater than in hypertension than in the control group. The concentric hypertrophy group and eccentric hypertrophy group suffered more serious damage of left ventricular diastolic function than the concentric remodeling group, and damage of left ventricular diastolic function in the concentric remodeling group was greater than that in the normal geometry group. The degree of cardiac diastolic function damage differed among patients with different left ventricular geometric patterns, when the cardiac structure was changed, the degree of cardiac diastolic function damage increased.

Diastole↗
PubMed2001

Measurement of bubble size distribution in protein foam fractionation column using capillary probe with photoelectric sensors.

Bubble size is a key variable for predicting the ability to separate and concentrate proteins in a foam fractionation process. It is used to characterize not only the bubble-specific interfacial area but also coalescence of bubbles in the foam phase. This article describes the development of a photoelectric method for measuring the bubble size distribution in both bubble and foam columns for concentrating proteins. The method uses a vacuum to withdraw a stream of gas-liquid dispersion from the bubble or foam column through a capillary tube with a funnel-shaped inlet. The resulting sample bubble cylinders are detected, and their lengths are calculated by using two pairs of infrared photoelectric sensors that are connected with a high-speed data acquisition system controlled by a microcomputer. The bubble size distributions in the bubble column 12 and 1 cm below the interface and in the foam phase 1 cm above the interface are obtained in a continuous foam fractionation process for concentrating ovalbumin. The effects of certain operating conditions such as the feed protein concentration, superficial gas velocity, liquid flow rate, and solution pH are investigated. The results may prove to be helpful in understanding the mechanisms controlling the foam fractionation of proteins.

Chemical Engineering↗
PubMed2001

Expression of angiogenic factors and apoptotic factors in leiomyosarcoma and leiomyoma.

Angiogenesis is essential for tumor growth and metastasis. Some angiogenic factors, such as vascular endothelial growth factor (VEGF), platelet-derived endothelial cell growth factor (PD-ECGF), transforming growth factor-alpha (TGF-alpha) and basic fibroblast growth factor (bFGF) are involved in increased angiogenic activity and disease progression in many carcinomas. However, there is little information regarding the association between angiogenic factors and leiomyosarcoma. Although there are abundant vessels in the sarcoma which enable it to easily receive nutrition and medicinal components, chemotherapy cannot effectively treat leiomyosarcoma. This means the resistance to anticancer drugs in leiomyosarcoma is very strong. However, the resistant mechanism is still unclear. In this study, expressions of VEGF, PD-ECGF, TGF-alpha, bFGF, intratumoral microvessel density (IMVD), and p53, Bcl-2 and Bax were examined by immunohistochemistry in 30 patients with leiomyosarcoma and 21 patients with leiomyoma. With regard to angiogenesis, PD-ECGF and TGF-alpha were closely associated with an increase in IMVD (p=0.012, 0.0196, respectively), and VEGF and PD-ECGF were significantly expressed in leiomyosarcoma compared with leiomyoma (p=0.041, 0.041, respectively). Although p53 expression in leiomyosarcoma was significantly higher than in leiomyoma (p=0.016), the frequency of p53 positivity was not so high (47%). On the other hand, the ratio of Bcl-2/Bax in leiomyosarcoma was significantly higher than that in leiomyoma (p=0.033). The findings of this study suggest that in leiomyosarcoma, angiogenic factors, such as PD-ECGF, VEGF and TGF-alpha expression may be involved in tumor angiogenesis, and the frequently high ratio of Bcl-2/Bax and expression of p53 gene mutation might be related to chemoresistance mechanism.

Angiogenesis Inducing Agents↗
PubMed2001

[Effect of unprepared and prepared "he zi" on contraction of isolated trachea smooth muscle in rabbits].

Isolated trachea smooth muscle in rabbits induced by Ach or KCl was adopted to study the effect of unprepared and prepared "He Zi". The results showed that unprepared "He Zi" couldn't affect the contraction of isolated trachea smooth muscle in rabbit induced by Ach or KCl, and that prepared "He Zi" couldn't affect the contraction of isolated trachea smooth muscle in rabbit induced by KCl. The results also showed that prepared "He Zi" could significantly inhibit the contraction induced by Ach. The inhibition effect may not be associated with cGMP, adrenergic receptor, and release of NO and prostaglandin, and was epithelium independent. Maybe the different content of tannic acid contributed to the different effect between unprepared and prepared "He Zi".

Acetylcholine↗
PubMed2001

Compensatory up-regulation of nitric-oxide synthase isoforms in lead-induced hypertension; reversal by a superoxide dismutase-mimetic drug.

Chronic exposure to low levels of lead causes hypertension (HTN) that is, in part, due to increased inactivation of nitric oxide (NO) by reactive oxygen species (ROS). The latter results in functional NO deficiency and compensatory up-regulation of NO synthase (NOS). We have previously shown evidence for increased hydroxyl radical (*OH) activity in rats with lead-induced HTN. Since in the biological systems *OH is primarily derived from superoxide (O2*) we hypothesize that lead-induced oxidative stress and HTN must be due to increased O2* production and as such could be ameliorated by administration of a cell-permeable O2* scavenger. We, therefore, studied the effects of the superoxide dismutase (SOD)-mimetic drug tempol (15 mmol/kg/day i.p. x 2 weeks) and placebo in lead-exposed (given lead acetate, 100 ppm in the drinking water for 12 weeks) and normal control rats. Lead exposure resulted in a marked elevation of blood pressure, a significant reduction in urinary NO metabolites (NO(chi)) excretion, and up-regulations of endothelial and inducible NOS abundance in the kidney, aorta, and heart and of neuronal NOS in the cerebral cortex and brain stem. Administration of tempol ameliorated HTN, increased urinary NO(chi) excretion, and reversed the compensatory up-regulation of NOS isoforms in rats with lead-induced HTN. These abnormalities recurred within 2 wk after discontinuation of tempol. In contrast to the lead-exposed rats, the normal control rats showed no change in either blood pressure, urinary NO(chi) excretion, or tissue NOS expression in response to either administration or discontinuation of tempol. Thus, the study supports the presence of increased O2* activity and its role in the pathogenesis of HTN and altered NO metabolism in lead-exposed animals.

Animals↗
PubMed2001

Cryopreservation of suckling pig hepatocytes.

To determine the best and simplest method for cryopreservation of pig hepatocytes, we compared immediate cryopreservation with cryopreservation after short-term culture. Suckling pig hepatocytes were isolated by a modified 2-step in situ collagenase perfusion method, suspended in serum-free medium, and preserved for 10 da by two cryopreservation methods. Serial measurements were made of cell viability, LDH release, synthesis of protein, urea and glucose, glucose-6-phosphatase (G-6-Pase) activity, and diazepam transformation after thawing. These measurements were performed on both groups of cultured hepatocytes, and on freshly isolated hepatocytes, which served as a control. High viability (>95%)of thawed hepatocytes was obtained and maintained in both cryopreservation groups. There were no significant differences in cell viability, protein synthesis, glucose synthesis, G-6-Pase activity, or diazepam transformation between the two cryopreservation groups. In the immediate cryopreservation group, urea synthesis was less than in the group with cryopreservation after short-term culture. Protein synthesis, glucose synthesis, and diazepam transformation were lower in both cryopreserved groups than in the controls. The results showed that a protocol of immediate cryopreservation of hepatocytes in RPMI-1640 medium containing 10% DMSO, hormones, growth factors, and 10% newborn bovine serum, together with rate-controlled freezing and rapid thawing, provides indices of cell viability and function during subsequent serum-free culture that are comparable to hepatocytes cryopreserved after short-term culture, except for lower urea production. This simple procedure can be used in studies of bioartificial liver and hepatocyte transplantation.

Animals↗
PubMed2001

[Relationship between growth potential of pine, population density of Monochamus alternatus and pathogenicity of Bursaphlenchus xyloophilus].

The results showed that the growth potential of pine (x) is negative related to the population density of Monochamus alternatus (y) and the pathoyenecity of Bursaphlenchus xyloophilus (z). But the population density of Monochamus alternatus is positively related to the pathogenicity of Bursaphlenchus xyloophilus. Three linear equations regression line were established as y = 1793.771 - 16404.47x, z = 31.80989 - 241.9274x, y = -407.611 + 70.51478z. Correlation coefficient is -0.8139, -0.8770 and +0.9864 respectively.

Animals↗
PubMed2001

Intracranial aneurysms: experience in treating 500 patients.

OBJECTIVE: To summarize the experience in surgical treatment of patients with intracranial aneurysms. METHODS: The measures used in the treatment of 500 patients with intracranial aneurysms were retrospectively reviewed with regard to timing of surgery, induced-hypotensive anesthesia, brain protection combined with temporal occlusion of the feeding artery, dynamically monitoring of transcranial Doppler ultrasound, antivasospasm treatment, techniques of direct surgery, and endovascular embolization. RESULTS: In 465 patients undergoing surgery, intraoperative rupture was observed in 27(6.2%), postoperative death in 13 (2.7%), hemipalsy in 8(2.2%), and vegetative state in 2 (5.0%). The operative mortality was 3.8% in 210 patients before 1990, while 1.9% in 255 patients after 1990. CONCLUSION: The outcome of patients with intracranial aneurysms can be markedly improved by comprehensive measures.

Adult↗
PubMed2001

[A study of the effect of protein kinase C on the expression of nitric oxide synthase mRNA in pulmonary artery smooth muscle in hypoxia].

OBJECTIVE: To investigate the effect of PKC on the expression of NOS mRNA in pulmonary artery smooth muscle cell(PASMC) in hypoxia. METHODS: RT-PCR was used to detect the expression of PKC alpha mRNA in PASMC of procine, and the effect of activator and inhibitor of PKC on the expression of cNOS mRNA in PASMC. RESULTS: The expression of PKC-alpha mRNA was higher in the PASMC in 48 and 72 h of hypoxia(P < 0.01), and the expression of cNOS mRNA was lower(P < 0.01). The expression of cNOS mRNA was significantly negatively correlated with the expression of PKC-alpha mRNA(P < 0.001). PMA, an agonist of PKC could reduce the expression of cNOS mNRA in hypoxia, while RO 31-8220, an inhibitor of PKC could inhibit it and enhance the expression of NOS mRNA(P < 0.01). The activator of NO, L-Arg and inhibitor, L-NAME had no effect on expression of PKC-alpha mRNA. CONCLUSION: The PKC can inhibit the expression of cNOS mRNA in PASMC in hypoxia. The effect of PKC in hypoxic pulmonary hypertension may be made by inhibiting the expression of cNOS mRNA and modulating NO. The site of the effect of PKC may be in upstream of NO. The mechanism of it needs to be studied further.

Animals↗
PubMed2001

Relationship between c-fos gene expression and delayed neuronal death in rat neonatal hippocampus following hypoxic-ischemic insult.

OBJECTIVE: To explore the mechanism of perinatal hypoxia-ischemia encephalopathy, we studied the expression of the c-fos gene and its relationship with delayed neuronal death in a rat model. METHODS: Cerebral hypoxia-ischemia was produced in 7-day-old SD rats using the Rice model. Reverse transcription PCR (RT-PCR), immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) were used to detect the expression of c-fos gene and cell apoptosis in the hippocampus. RESULTS: The selective expression of c-fos and delayed cell apoptosis were observed in the hypoxia-ischemia hippocampus. Expression of the c-fos gene was seen in the CA4 and cingulate sulcus neurons, and apoptosis was observed in the CA1 neurons. CONCLUSION: Transient expression of the c-fos gene may induce cerebral cell apoptosis, and may have complex relations with delayed cell death.

Animals↗
PubMed2001

[Microsatellite instability in renal cell carcinoma and its mechanisms].

OBJECTIVE: To study the expression of microsatellite instability (MSI) in renal cell carcinoma (RCC) and its relationship with gene mutation. METHODS: Tumor samples from 34 patients with RCC were analyzed for MSI by PCR. RT-PCR was used to evaluate the expression of mRNA of 5 human mismatch repair (MMR) genes in RCC and RCC cell lines. Mutation of hMLH1 gene coding regions was detected by PCR-SSCP. PCR was used to check the mutations of TGF-beta R II gene and BAX gene in 15 MSI-positive samples of RCC. RESULTS: Microsatellite changes were detected in 15 of 34 patients with RCC (44.1%). It might be associated with the progression of this disease. There were 3 of 15 MSI-positive RCC cases without expression of MMR gene hMLH1, and in 3 of 15 cases its expression was decreased. All 5 MMR genes were expressed in normal and RCC 949 cell line. There were three mutations in 15 MSI-positive cases. Frame shift mutation of TGF beta R II gene and BAX gene was found in 6 and 4 of the 15 cases with MSI, respectively, but it was not found in MSI-negative RCC and normal tissue. CONCLUSION: MSI and expression of MMR genes are associated events in RCC. The effect of gene mutation on tumorgenerasis may be related to MSI.

Adaptor Proteins, Signal Transducing↗
PubMed2001

[Effects of hypoxia on the expression of protein kinase C mRNA in pulmonary artery smooth muscle and endothelial cell].

OBJECTIVE: To investigate the effects of hypoxia on the expression of PKC mRNA in pulmonary artery smooth muscle cells (PASMC) and endothelial cells. METHODS: In situ hybridization technique was used to detect the expression of PKC mRNA in different segments of pulmonary artery smooth muscle and endothelial cell (EC) in rats, and the effect of hypoxia on the expression of PKC alpha mRNA in pulmonary artery smooth muscle and endothelial cells in vivo and in vitro. RESULTS: PKC alpha mRNA was expressed in normal PASMC and EC in rats. The expression of PKC alpha mRNA was higher in the PASMC of intra-acinar pulmonary arteriole than that of muscular arteriole (P < 0.01). In 14 and 28 days of hypoxia, the expression of PKC alpha mRNA was higher both in EC of intraacinar pulmonary arteriole and muscular arteriole and PASMC of intra-acinar pulmonary arteriole (P < 0.01). After 14 days of hypoxia, the expression of PKC alpha mRNA was not significantly changed. But by 28 days, it became significantly higher (P < 0.01). PKC alpha mRNA was expressed in normal PASMC and EC in pigs in vitro. After 1 h of hypoxia, no change was detected, but PKC alpha mRNA expression was significantly higher after 48 h and 72 h of hypoxia in PASMC and EC in vitro (P < 0.01). CONCLUSIONS: Hypoxia can promote expression of PKC alpha m RNA in PASMC and EC, especially in the PASMC of intra-acinar pulmonary arterioles. PKC alpha may play an important role in the development of hypoxia pulmonary hypertension.

Animals↗
PubMed2001

[Effect of zhuhuang frost on wound hydroxy-proline level after anal operation].

OBJECTIVE: To observe the effect of Zhuhuang Frost (ZHF), an external preparation of Chinese herbal medicine, on level of hydroxy-proline (Hyp) in surgical wound after anal operation. METHODS: Fifty postoperational patients after low position simple operation of anal fistula were randomly divided into two groups and treated with ZHF and Mayinglong Musk hemorrhoidal paste (MMHP) respectively. The level of Hyp in granulation of wound was tested using alkaline hydrolysis assay at the 3rd, 7th and 14th day after operation respectively. RESULTS: The Hyp level tested at the 7th and 14th day after operation in the ZHF treated group was higher than that in the MMHP treated group, but those tested at the 3rd postoperational day in the two groups was not different significantly. CONCLUSION: ZHF could increase the Hyp level in postoperational granulation of wound after anal operation.

Administration, Topical↗
PubMed2001

[Studies on chemical constituents from Dracocephalum moldavica L].

OBJECTIVE: To study the chemical constituents from the whole plant of Dracocephalum moldavica. METHOD: The compounds were isolated using RA polystyrene resin and silica gel column chromatography, and the structures were elucidated by means of spectral method. RESULT: Four compounds were identified as tilianin, agastachoside, acacetin and oleanolic acid. CONCLUSION: All the compounds were isolated from this plant for the first time.

Flavones↗
PubMed2001

[Studies on the chemical constituents from Myristica yunnanensis Y. H. Li].

OBJECTIVE: To study the chemical constituents of Myristica yunnanensis. METHOD: Compounds were isolated using silica gel and reversed-phase C18 column chromatography, their structure were identified by means of spectral method. RESULT: Five known compounds were identified as otobain(I), beta-sitosterol(II), ergosterol(III), afzelin(IV) and quercetrin(V). CONCLUSION: Compounds IV and V were isolated first from Myristica.

Flavonoids↗
PubMed2001

[Studies on chemical constituents of oligostilbenes from Vitis davidii Foex].

OBJECTIVE: To study the chemical constituents of oligostilbenes from Vitis davidii. METHOD: Compounds were isolated with polystyrene resin RA, silica gel and C18 column chromatography. The structures were elucidated by means of spectroscopic evidence. RESULT: Seven compounds were obtained and identified as resveratrol, heyneanol A, ampelopsin E, amurensin B, (+)-epsilon-viniferin, vitisin A and amurensin G. CONCLUSION: All the compounds were isolated from this plant for the first time.

Benzofurans↗
PubMed2001

[Studies on chemical constituents of Umbilicaria esculenta (Miyoshi) minks].

OBJECTIVE: To study the chemical constituents from the fruit bodies of Umbilicaria esculenta. METHOD: Five compounds were isolated from the ethanolic extract of this plant by all kinds of column chormatography, and structures were identified by spectroscopic analysis. RESULT: Five compounds were identified as ethyl orsellinate, orsellinic acid, orcinol, lecanoric acid and lecanorin. CONCLUSION: Ethyl orsellinate, orsellinic acid, orcinol and lecanorin were isolated from this plant for the first time.

Lichens↗