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Biomedical subjects

H Song

Publications and source records attributed to H Song.

At least 199 records · Page 11Linked to original sources
PubMed1996

[Selective arterial catheterization in the management of drug-resistant choriocarcinoma].

OBJECTIVE: In order to save the life of the patients with drug-resistant choriocarcinoma due to improper treatment, selective arterial catheterization was used. METHODS: All the 71 cases were treated with systemic chemotherapy together with pelvic selective arterial chemotherapy. 5 of them had arterial chemotherapy plus arterial embolization for hemorrhage. In 13 patients who had lung metastasis, intraarterial injection of methotrexate (MTX) through bronchial arterial was added. RESULTS: 55 of 71 (77.8%) achieved complete remission and 10 (14.1%) had partial remission. One patient failed to follow-up. 5 died of various causes during hospitalization. On Follow-up 12 had survived for more than 5 years with no signs of recurrence. 2 of them had childbirth after recovery. CONCLUSION: Systemic intravenous infusion chemotherapy in combination with arterial chemotherapy is useful for drug-resistant choriocarcinoma. In patients with intraperitoneal hemorrhage caused by tumor rupture, selective arterial embolization should be used as emergency treatment to effectively control the bleeding, in order that patients will have a chance for further chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

[Cardiotoxicity of 5-fluorouracil].

OBJECTIVE: To determine the possibility and magnitude of cardiotoxicity following high dose intravenous infusion of fluorouracil (5-FU). METHODS: A prospective clinical study was performed on 104 patients with choriocarcinoma and invasive mole. 5-FU was administered by slow intravenous infusion in 5% glucose 500 ml for 8 hours at doses of 28-30 mg.kg-1.day-1 when used as a single agent treatment or 24-26 mg.kg-1.day-1 when used in combination with kengshengmycin (KSM). The total cycles of treatment with 5-FU + KSM were 109 and those of 5-FU or KSM each used as a single agent were 71 and 12 respectively. The cardiac functions were monitored by cardiac symptoms, ECG and serum cardiac enzymes before and after 5-FU infusion. RESULTS: Among the 192 treatment cycles tachycardia, palpitation or cardiac distress were observed in 14 cycles. ECG showed changes of ST or T waves in 8 cycles, sinus tachycardia in 3 cycles. The results of serum cardiac enzyme determinations were variable. The diagnostic criteria of cardiotoxicity were appearances of abnormalities manifested in any two of the three monitor items. The incidence of cardiotoxicity was 4.2% in 5-FU group, 4.6% in 5-FU + KSM group and 0% in KSM group. All episodes were mild, reversible spontaneously after cessation of chemotherapy and did not reappear in subsequent chemotherapeutic cycles. Seven patients with definite cardiac diseases before chemotherapy were given 5-FU treatment, but no obvious aggravation of cardiotoxicities were observed even with repeated 5-FU treatments. CONCLUSION: Only occasional cardiotoxicities were observed in 5-FU treatments. They were rather mild and reversible. The incidence of cardiotoxicity might be reduced with emphasis on strict observance of the treatment regimen in regard to the dosage used, the speed of the infusion and attention to the treatment of any side-effects.

Adult↗
PubMed1996

[Effects of blood pressure day-nocturnal rhythm and endothelin in patients of sleep apnea syndrome].

OBJECTIVE: To analyse the change of blood pressure and endothelin in sleep apnea syndrome. METHODS: The ambulatory blood pressure, echocardiogram and plasma endothelin in 164 cases of hypertension and normal controls with or without sleep apnea syndrome (SAS) were examined. The patients were divided into four groups and 41 cases were in each group. RESULTS: The results showed that in a number of the patients of sleep apnea with or without hypertension blood pressure day nocturnal rhythm disappeared and endothelin increased (18.2 +/- 5.7 ng/L and 13.2 +/- 4.4 ng/L) The difference of nocturnal blood pressure and endothelin between SAS groups and non-SAS groups (11.7 +/- 3.9 ng/L and 4.3 +/- 2.1 ng/L) were statistically significant (P < 0.05 and P < 0.01). CONCLUSION: It was suggested that the SAS patients might be due to cyclical hypoxemia and nerve-endocrine abnormality activating endothelin, and other vasoactive peptides with increased blood pressure during sleep and enhance the damage to target organs.

Adult↗
PubMed1996

[Curcuma longa L. tuber yield simulation model and its application under combined agronomic measures for good-quality, high-yield and obvious economic results].

A design of second order orthogonal rotative regression was developed and field tested, and the tuber models for yield, quality and benefit were simulated and built. The effect of agronomic measures on the tuber yield is plant density > phosphorus > sowing date > nitrogen > potassium. There is a clear interrelation effect among agronomic measures. The results of simulation experiment have shown that the optimal combination of farming practices can greatly increase the tuber yield, quality and benefit, and is adjusted according to climate, soil, ferilizer or manure sources, and so on.

Computer Simulation↗
PubMed1995

A protein kinase C inhibitor attenuates cyanide toxicity in vivo.

We have examined the effect of pretreatment with a potent protein kinase C (PKC) inhibitor, 1-(5-isoquinoline-sulfonyl)-2-methylpiperazine (H-7), against metabolic alterations induced by sodium cyanide (NaCN), 4.2 mg/kg, in brain of anesthetized male micropigs (6-10 kg). Brain high energy phosphates were analyzed using a 31P nuclear magnetic resonance (NMR) spectroscopic surface coil in a 4.7 Telsa horizontal bore magnet. H-7, 1 mg/kg, was given intravenously (i.v.) 30 min before NaCN challenge (H-7 + CN-). Prior to NaCN, H-7, or H-7 + CN- administration, baseline 31P resonance spectra of 1-min duration were acquired for 5-10 min, and continued for an additional 60 min following i.v. NaCN injection, each animal serving as its own control. Peaks were identified as phosphomonoester (PME), inorganic phosphate (Pi), phosphodiester (PDE), phosphocreatine (PCr) and adenosine triphosphate (ATP), based on their respective chemical shifts. Without H-7 pretreatment, NaCN effects were marked by a rising Pi and a declining PCr peak 2 min after injection, with only 2/5 of the animals surviving the 60 min experiment. Through a pretreatment period of 30 min, H-7 did not affect baseline cell energy profile as reflected by the 31P-NMR spectra, but in its presence, those changes (i.e. diminishing PCr and rising Pi peaks) elicited by NaCN were markedly blunted; 4/5 of the animals in this group survived the NaCN challenge. It is proposed that H-7, a pharmacologic inhibitor of PKC, may be useful in CN- antagonism, underscoring the role of PKC in cyanide intoxication.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1995

Dissection of protein-carbohydrate interactions in mutant hen egg-white lysozyme complexes and their hydrolytic activity.

Trp62 in the binding subsite B of hen egg-white lysozyme shows general features often observed in protein-carbohydrate interactions including a stacking interaction and a hydrogen bonding network with water molecules. A previous report by our group showed that the perturbation of these interactions by substitution of Trp62 with tyrosine or phenylalanine affects the substrate binding modes and also enhances the hydrolytic activity. In order to elucidate the relationship between structural and functional changes of these protein-carbohydrate interactions, the Trp62Tyr and Trp62Phe mutants complexed with the substrate analogue, (GlcNAc)3, were analyzed at 1.8 A resolution by X-ray crystallography. The overall structures of the mutant enzymes are indistinguishable from that of the wild type enzyme. Although the wild-type enzyme binds (GlcNAc)3 in only one binding mode (A-B-C), the Trp62Tyr mutant binds (GlcNAc)3 in two binding modes (A-B-C, B-C-D) and the Trp62Phe mutant has an even weaker binding mode. The aromatic rings of Tyr62 and Phe62 maintain their interactions with the carbohydrate molecules, but make fewer stacking interactions with the GlcNAc in the B site than the wild-type enzyme does. The hydroxyl group of Tyr62 interacts weakly with a water molecule which mediates hydrogen bonding in the GlcNAc residues in the B and C sites. The C-6 hydroxyl group of the GlcNAc residue in the C site rotates around the C-5-C-6 bond to complete the hydrogen bond network in the Trp62Tyr mutant-(GlcNAc)3 complex. On the other hand, this hydrogen bonding network does not form in the Trp62Phe mutant-(GlcNAc)3. In addition to these structural studies, the kinetic parameters of the hydrolysis of 4-methylumbelliferyl N-acetyl-chitotriose, ((GlcNAc)3-MeU), have been determined in order to further characterize the enzymatic properties of these mutant lysozymes. This demonstrates that the modulation of the hydrogen bonding network, including the flexible part of the carbohydrate and water molecules and/or the slight reduction of stacking interaction in the B site, alters the binding mode toward the carbohydrate and induces an enhancement of the hydrolytic activity.

Acetylglucosamine↗
PubMed1995

Structure of a conformationally constrained Arg-Gly-Asp sequence inserted into human lysozyme.

To examine the effect of a conformational constraint introduced into the Arg-Gly-Asp (RGD) sequence on cell adhesion activity, we constructed a mutant protein by inserting an RGD-containing sequence flanked by two Cys residues between Val74 and Asn75 of human lysozyme. The CRGDSC-inserted lysozyme was expressed in yeast, purified, and designated as Cys-RGD4. Using baby hamster kidney cells, Cys-RGD4 was shown to possess even higher cell adhesion activity than that of the RGDS-inserted lysozyme, RGD4. The Cys-RGD4 protein was co-crystallized with a lysozyme inhibitor, tri-N-acetylchitotriose, and the three-dimensional structure was determined at 1.6-A resolution by x-ray crystallography. In contrast to RGD4, the inserted RGD-containing region of Cys-RGD4 was well defined. The structural analysis revealed that the two inserted Cys residues form a new disulfide bond in Cys-RGD4, as expected, and that the RGD region assumes a type II' beta-turn conformation of Gly-Asp with a hydrogen bond between the C = O of Arg and the H-N of Ser. In addition, it was confirmed that two more hydrogen bonds are present in the RGD region of the Cys-RGD4 lysozyme. These results suggest that the conformation of the RGD-containing region is rigid and stable in the Cys-RGD4 molecule and that the type II' beta-turn structure of RGD is essential for binding to integrins with high affinity.

Asparagine↗
PubMed1995

[Pathological study of hepatoid gastric adenocarcinomas].

Routine examination of pathologic sections in 500 cases of primary gastric adenocarcinomas was carried out by light microscopy. Regions of hepatocellular carcinomatoid differentiation were discovered in 12 of the 500 cases. In 11 of them, histopathologic features were described in great detail and the hepatocellular carcinomatoid regions were studied by four kinds of immunohistochemistrical methods. The results indicate that positive staining for AFP was seen in 9 cases but negative in 9 controls, weakly positive for CEA in 10 cases, but strongly positive in 8 controls. Staining for alpha 1-AT and alpha 1-ACT showed no differences as compared to controls. The clinical pathological features and its relationship with AFP are discussed. It is suggested that hepatoid gastric adenocarcinoma is a subtype of gastric adenocarcinoma.

Adenocarcinoma↗
PubMed1995

[Personal characteristics as risk factors of endometriosis].

203 patients with pelvic endometriosis, all Beijing resident, were collected from the Peking Union Medical College Hospital and the Beijing Obstetrical and Gynecological Hospital. The diagnosis of endometriosis was confirmed by pathological examination of surgical specimens in 186 patients and by aspiration of chocolate substance under laparoscopy in 17. Two population controls, age matched +/- 1 year, were randomly selected for each patient from the same residential area, after careful pelvic examinations and ultrasonographies. A questionnaire for any possible risk factors to endometriosis was developed and with this questionnaire a face to face interview for each subject was carried out by the trained interviewers. All interviews were tape recorded and calculated in a AST 386 computer. The continuous logistic regression for matched sites was used to obtain a maximum likelihood point and to control the potential confounding effects of selected variables. Relative risk (RR) substituted for odds ratio together with the 95% confidence intervals was estimated. All the results were adjusted for the variables of the model including some relevant factors of menstruation, pregnancy and contraception. An increased risk for endometriosis was found to be related to women who had a higher level of education. Even it was adjusted for age of first marriage and pregnancy, gravidity, parity, contraception and all other variables of the model, the relative risk was 1.84 for endometriosis. Therefore, it is the education level itself that plays a true role in development of endometriosis. Although there was a trend in risk for endometriosis in height, it was statistically insignificant.(ABSTRACT TRUNCATED AT 250 WORDS)

ABO Blood-Group System↗
PubMed1995

Repetitive, low-dose tissue plasminogen activator for clearance of experimental vitreous hemorrhage.

PURPOSE: To investigate the effectiveness of repetitive, low-dose tPA for clearance of experimental vitreous hemorrhage. METHODS: The model vitreous hemorrhage was produced by intravitreal injection of 0.05ml of autologous citrated whole blood in 14 rabbits (28 eyes). One week after the creation of vitreous hemorrhage, the eyes were randomly separated into 3 groups. Groups 1 and 2 received two injections of 5 or 25 micrograms of tPA, respectively, with one injection in a 7-day interval. Group 3 received two injections of PS in the same way. RESULTS: The clearance of vitreous hemorrhage in tPA-treated groups was significantly faster than that in the control group (P < 0.05, or P < 0.01). However, there was no statistically significant difference between the two tPA-treated groups. Not any retinal toxicity was detected by ERG, light microscopy, and transmission electron microscopy examinations. CONCLUSIONS: Repetitive injections of low-dose tPA were effective in the treatment of experimental vitreous hemorrhage. Whether it is effective on the clearance of vitreous hemorrhage in human eyes needs further investigation.

Animals↗
PubMed1995

[Changes of intestinal flora in senile mouse models and the antagonistic activity of the root of Astragalus membraceus (Fisch) Bge].

Inhaled by mice, ozone induced stronger free radical reaction in the organism and led to a series of changes similar to senility. In this way the senility mouse models were established to observe the changes of intestinal flora in senile mice. The senile mice were given the root of Astrogolus membraceus decoction orally. The results showed that the imbalance of intestinal flora in these mice was recovered.

Aging↗
PubMed1994

Structural changes of active site cleft and different saccharide binding modes in human lysozyme co-crystallized with hexa-N-acetyl-chitohexaose at pH 4.0.

Human lysozyme was co-crystallized with hexa-N-acetyl-chitohexaose, (GlcNAc)6, at pH 4.0 and 4.0 degrees C in a new orthorhombic form, where two protein molecules, MOL1 and MOL2, were contained in an asymmetric unit. The three-dimensional structure was refined to an R-factor of 17.0% at 1.6 A resolution. It was found that (GlcNAc)6 had already been cleaved to (GlcNAc)4 and (GlcNAc)2. In MOL1, (GlcNAc)4 was bound to the A, B, C, and D subsites, and binding sites of (GlcNAc)2 were close to the E and F subsites proposed on the basis of model building by Phillips and his colleagues. In MOL2, only the (GlcNAc)4 moiety could be found in the A, B, C and D subsites. Significant shifts of the backbone atoms were observed in the region of residues 102 to 120, which composed one side of the wall of the active site cleft. Consequently, the active cleft, with respect to the saccharide binding sites A, B and C, is narrower in both protein molecules. The residues 109 to 111 in site D of MOL1 are moved toward saccharide residue D, whereas those of MOL2 are only slightly shifted. In spite of these facts, the saccharide residues in site MOL1 and MOL2 are moved inside of the cleft. The distribution of water molecules and the hydrogen bond network in site D differ between the structures of MOL1 and MOL2. These structural changes in the active site cleft may be responsible for accommodating the substrate and releasing the products of hydrolysis. These results suggest that the three-dimensional structures of MOL1 and MOL2 remain in intermediate states between a transition state and an enzyme/product complex state.

Binding Sites↗
PubMed1994

Novel regulation of pyruvate dehydrogenase phosphatase purified from anaerobic muscle mitochondria of the adult parasitic nematode, Ascaris suum.

Pyruvate dehydrogenase (PDHb) phosphatase has been purified to apparent homogeneity from mitochondria of the adult parasitic nematode, Ascaris suum. The enzyme is a heterodimer of 89 and 50 kDa, as judged by SDS-polyacrylamide gel electrophoresis. It appeared to copurify with its substrate, pyruvate dehydrogenase (E1) and could be separated by chromatography on Superose 12 in the presence of 0.5 M NaCl. Phosphatase activity was absolutely dependent on Mg2+, with an apparent Km of about 4 mM. In contrast to PDHb phosphatases from other sources, the ascarid enzyme was not stimulated by Ca2+ or spermine, but it was stimulated by L-malate, the major mitochondrial substrate in A. suum. L-Malate had no effect on the dephosphorylation of isolated [32P]E1, but it decreased the apparent Km of the phosphatase for 32P-pyruvate dehydrogenase complex or [32P]E1 in the reconstituted complex about 4-6-fold, suggesting that the dihydrolipoyl transacetylase (E2) core was necessary for malate activation. The activity of the pyruvate dehydrogenase complex (PDC) in isolated A. suum muscle mitochondria was significantly greater than that reported for other mitochondria, and the majority of the PDC appeared to be in the phosphorylated inactive state. Incubation of intact phosphorylating A. suum muscle mitochondria in the absence of substrate and the presence of an uncoupler did not lead to an activation of PDC activity. In contrast, incubation in malate plus Mg2+ markedly increased PDC activity. These results contrast markedly with those reported for aerobic mitochondria and suggest that the regulation of PDC activity in these anaerobic organelles differs significantly from that of their mammalian hosts.

Anaerobiosis↗