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Biomedical subjects

F Guo

Publications and source records attributed to F Guo.

At least 73 records · Page 4Linked to original sources
PubMed1996

Effects of Coriolus versicolor polysaccharides on superoxide dismutase activities in mice.

AIM: To study if Coriolus versicolor polysaccharides (CVP) influence the superoxide dismutase (SOD) activities in mice. METHODS: Normal, tumor-bearing, and radiated ICR mice were injected ip with CVP daily for 3-15 d. The SOD activity was assayed by epinephrine autoxidation test. RESULTS: The SOD activities in lymphocytes and thymus were increased by CVP in both the normal mice with or without delayed hypersensitivity (DH). In tumor-bearing mice, CVP exerted not only inhibitory effects on tumor, growth and SOD activity in tumor tissue but also complete or partial restorative effects on the suppressed DH and on the declined SOD activities in lymphocytes, spleen, and thymus. The total SOD and manganese-containing SOD (MnSOD) activities in lymphocytes and thymus were dose-dependently enhanced by CVP (5-20 mg.kg-1) on d 3 after the tumor transplantation. In the mice exposed to 60Co (3 or 6 Gy), DH and SOD activities were dose-dependently decreased. These changes were completely or partly prevented by CVP. CONCLUSION: CVP exerted the favorable effects on SOD activities in mice. Coriolus versicolor polysaccharides (CVP) exert inhibitory effects on experimental and clinical tumors. These effects are presumed to be mediated mainly by host-defence mechanism, especially immunological responeses. Superoxide dismutase (SOD) plays an important role in protecting cells against superoxide radical (O2-.) damages and over-production of O2-. or SOD abnormities exist in many diseases. The present study was to investigate if the CVP could exert some favorable effects on SOD activities in vivo.

Animals↗
PubMed1995

High-fat feeding during pregnancy and lactation affects offspring metabolism in rats.

This study was designed to examine the interaction of pregnancy and dietary fat on pregnancy outcome and offspring metabolism in rats. Wistar rats were divided into four groups: HF (40% fat by weight) feeding and pregnant (HFP, n = 15); HF nonpregnant control (HFNP, n = 10); control diet (4.5% fat) and pregnant (CHP, n = 12); and control diet nonpregnant (CHNP, n = 10). Rats were fed the same diets throughout gestation and lactation and were sacrificed at weaning. Litter size was kept at six pups with extra pups killed at birth. HF-fed dams had significantly less caloric intake than control counterparts. HFP had similar body weight changes as CHP during gestation and lactation, whereas HFNP had significantly higher weight and fat content than CHNP. There was no difference in pup's birth weight. However, significantly more HF dams cannibalized their pups. Newborns delivered to HF-fed dams had higher insulin/glucose ratios than CH pups. HFP weanlings weighed more, had more body fat (%), higher liver weight, liver lipid content, and higher blood glucose and triglyceride levels than CHP weanlings. The long-term effects of these metabolic abnormalities need to be further examined.

Animals↗
PubMed1995

Cell damage and liberation of nitric oxide synthase in rat heart induced by endotoxin administration.

To evaluate the relationship between cardiovascular injury and the pathological aspect of the liberation of the nitric oxide synthase in endotoxin shock, Wistar rats were injected intraperitoneally with 10 mg/kg E. coli endotoxin and the cardiovascular changes were observed chronologically by immunohistochemical and electron microscopic techniques at 2, 4, 8 and 12 h respectively after endotoxin administration. Light microscopically, irregular contraction of cardiomyocytes was observed in the early stage. After 8 h of endotoxin administration, occasional disintegration of the myocytes as well as lysis of myofibrils became prominent, and diminished stainings of myoglobin and actin were seen in these myocytes. Ultrastructurally, increased pinocytotic vesicles were observed in endothelial cells associated with widened intercellular spaces, and vacuolization of endothelial and medial cells of the vasculature. In cardiomyocytes, swelling of mitochondria and interstitial edema were noted at 12 h after endotoxin administration. Immunohistochemically, an increased permeability of albumin was noted in the myocytes and vasculature and nitric oxide synthase was localized on the cytomembrane of the endothelium of the coronary arteries in control rats. After endotoxin administration, the reaction products of nitric oxide synthase increased in the endothelial and medial cells, and cardiomyocytes. These results suggest that the increased activity of nitric oxide synthase is an important factor in the excessive production of nitric oxide and in promoting the pathologic changes in the cardiovascular system after endotoxin administration.

Animals↗
PubMed1994

Leng et al. reply.

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Journal Article↗
PubMed1994

Prostaglandin endoperoxide-H synthase (PGHS) activity and immunoreactive PGHS-1 and PGHS-2 levels in human amnion throughout gestation, at term, and during labor.

Prostaglandins (PGs) are of primary importance in the initiation and maintenance of labor in women. A major intrauterine source of prostaglandins is the amnion, which synthesizes increased amounts of PGE2 at term labor. Because PG endoperoxide-H synthase (PGHS) catalyzes the rate-limiting step of PG synthesis from arachidonic acid, we investigated the changes in amniotic PGHS specific activity during gestation and at term and preterm labor. Also, we determined the level of immunoreactive PGHS protein in the amnion to evaluate the mechanisms by which PGHS activity may be regulated. PGHS specific activity, measured at the amount of PGE2 produced by amnion microsomes under optimal conditions, was 18.2 +/- 3.7 pg PGE2/micrograms protein.min (mean +/- SE; n = 19) at term (37-42 weeks gestation) before the spontaneous onset of labor. PGHS specific activity was significantly higher after spontaneous term labor (38.9 +/- 6.0 pg PGE2/micrograms protein.min; n = 19; P < 0.05). Amnion samples from preterm (< 36 weeks gestation) nonlaboring patients contained low levels of PGHS specific activity (5.9 +/- 1.8 pg PGE2/micrograms protein.min; n = 9), which increased significantly with spontaneous preterm labor (28.3 +/- 6.8 pg PGE2/micrograms protein.min; n = 10; P < 0.05). Longitudinal analysis of the data showed that PGHS specific activity was low in the first and second trimesters of gestation, but increased dramatically before labor onset at term. We detected PGHS protein in all microsomal samples, with an antiovine PGHS antibody recognizing both PGHS-1 and -2 isoforms of the enzyme. However, there was no correlation between PGHS specific activity and the amount of immunoreactive PGHS protein. Using an antibody specific for PGHS-2, we detected immunoreactive protein in only 9 of the 25 tissues examined and found no correlation between PGHS specific activity and the amount of PGHS-2 protein. These results suggest that 1) PGHS specific activity in the amnion increases sharply before the onset of labor at term; 2) further increases in specific activity occur during term and preterm labor; and 3) the specific activity of PGHS in the amnion is not related directly to the amount of immunoreactive enzyme protein.

Amnion↗
PubMed1994

Regulation of prostaglandin endoperoxide H synthase by glucocorticoids and activators of protein kinase C in the human amnion.

Since glucocorticoids decrease and protein kinase C (PKC) activators increase amniotic PGE2 production, the possibility that they regulate the activity of prostaglandin endoperoxide H synthase (PGHS), the rate-limiting enzyme of prostaglandin synthesis from arachidonate, was investigated. Glucocorticoids inhibited the production of PGE2 from exogenous arachidonate specifically and in a concentration dependent fashion. Furthermore, cortisol decreased PGHS activity and the amount of PGHS protein in amnion microsomes, and reduced the rate of recovery of PGHS after acetylsalicylic acid (ASA) pretreatment. Actinomycin D blocked the inhibition of PGHS recovery by cortisol, but did not suppress the spontaneous recovery of the enzyme, indicating that the glucocorticoid induced a post-transcriptional inhibitor of PGHS synthesis. PKC-activating phorbol esters, such as 12-tetradecanoyl phorbol 13-acetate (TPA) increased the synthesis of PGE2 from exogenous arachidonate, also in a specific and concentration dependent manner. PGHS recovery after ASA treatment was enhanced by TPA. PGHS activity and protein concentrations were increased by phorbol ester treatment; however, this was apparent only in tissues in which the concentrations of PGHS were initially low. These results show that the synthesis of PGHS is positively and negatively regulated in the human amnion by PKC and glucocorticoids, respectively, and suggest that effectors using these pathways may regulate the enzyme in vivo.

Amnion↗
PubMed1994

[Pathological studies on alveolar hydatid in gerbils treated with albendazole and praziquantel].

Pathological changes in alveolar hydatids from experimentally infected gerbils were studied after administration of albendazole or praziquantel. The animals were divided into several groups including the control one, and drugs of different dosages were given separately to different groups with diverse durations of infection. According to the microscopical observation, the hydatids could be categorized into 3 grades: grade I, degenerated cysts; grade II, stable cysts (showing no proliferation); grade III, proliferated cysts. Larger proportion of grade I cysts were found in the group treated with albendazole at high dosage (33.3%) and the two groups treated with praziquantel (25.0% and 16.3%). The proportion of grade I cysts in gerbils with shorter duration (45 d) of infection was larger than those with longer duration (60 d). Lymphocyte infiltration to various extent was present surrounding the alveolar hydatid cysts in all the treated groups. More marked infiltration of lymphocytes was observed in albendazole treated gerbils (106.9 +/- 34.3-300.1 +/- 59.5) (P < 0.001). However, the combined medication of albendazole and praziquantel was less efficacious.

Albendazole↗
PubMed1990

[Detection of erythrocyte immune function and circulatory immune complex in myasthenia gravis].

The circulating immune complexes (CIC) and erythrocyte immune function in myasthenia gravis were studied. In order to examine CIC in the patients with myasthenia gravis the complement sensitized yeast cell agglutination (CSYCA) test and anti-C3-ELISA were used. The CIC positive rate was 92.3% in the patients tested. The CIC test was all negative in the normal control subjects. The levels of CIC were remarkable elevated in the patients with myasthenia gravis (P less than 0.01). It was found that the rosette rate of red blood cell C3b receptor was 11.27 +/- 3.27% in the CIC negative patients with myasthenia gravis and 17.60 +/- 5.10% in CIC negative patients with myasthenia gravis. The erythrocyte immune function decreased remarkably in the CIC positive patients with myasthenia gravis (P less than 0.05). The relationship between the decrease of the erythrocyte immune function and myasthenia gravis is discussed.

Agglutination Tests↗
PubMed1989

[Preliminary study on the immune function of red cells in patients with pregnancy-induced hypertension].

This study compared the immune adherent function of red cells, circulating immune complex (CIC) and T lymphocyte immune function in cases of pregnancy induced hypertension (30 cases) and normal pregnancy (30 cases). In the former group the rosette rate of red cells C3b receptor was 8.8 +/- 3.2% (normal rate: 19.4 +/- 6.0%), and rosette rate of E-RFC was 46 +/- 2 +/- 7.3% (normal rate: 62.3 +/- 6.4%). In women with normal pregnancy, the former was 16.9 +/- 4.8%, and the latter was 58.0 +/- 8.3%. In women with pregnancy induced hypertension, the immune adherent function of red cells and T lymphocyte immune function were both lower than those in normal pregnant women, while CIC was higher. In normal pregnant women, the immune adherent function of red cells and T lymphocyte immune function were lower than those in the non-pregnant, while CIC was higher. The mechanism and significance of the red cells immunological adherent function in pregnancy induced hypertension were discussed.

Antigen-Antibody Complex↗
PubMed1989

[Enhancement of the therapeutic effect and red cell immune function by radix Trichosanthis in mice bearing Ehrlich ascites carcinoma].

Various red cell immune functions were determined in 60 mice bearing Ehrlich ascites carcinoma treated and untreated with Radix Trichosanthis(RT), and compared with these of 30 normal mice. In mice bearing Ehrlich ascites carcinoma treated with RT, the rosette formation of red cell C3b receptor, the rosette formation of red cell immune complex, the rosette formation rate of red cell round cancer, the rate of PMN phagocytosis were enhanced, and the activity of superoxide dismutase (SOD) was satisfactory higher than those in mice bearing Ehrlich ascites carcinoma untreated with RT, and almost same as those in normal mice, while the rosette inhibition rate of red cell C3b receptor in serum was satisfactory lower than that in mice bearing Ehrlich ascites carcinoma untreated with RT, and almost same as that in normal mice.

Animals↗
PubMed1984

Isolation and some characterization of the prothoracicotropic hormone from Bombyx mori.

The prothoracicotropic hormone (PTTH) was isolated from adult heads of Bombyx mori. Fifty micrograms of pure PTTH was obtained from 648,000 heads through a 15-step purification procedure with a 2 X 10(6)-fold purification and an 8% recovery. Chemical analyses of this PTTH have shown that it is a single-chain peptide consisting of 40-43 amino acid residues (MW, 4330-4740), the N-terminus of which is glycine. As little as 0.1 ng of PTTH elicited adult development in a debrained pupa of Samia cynthia ricini. Five picograms of PTTH directly stimulated the prothoracic glands in vitro so as to enhance ecdysone release. The hemolymph ecdysteroids of brainless Samia pupae that were developed by PTTH injection increased with essentially the same pattern as in developing normal pupae.

Amino Acid Sequence↗
PubMed1981

Observations of the blood supply to the fibula.

In the surgery of upper and lower extremities autotransplantation of the fibula is often used to bridge extensive bone defects. However, insufficient blood supply affects the long-term results. Microsurgery yields better results. We investigated the blood supply of the fibula to guarantee a careful operation method and the selection of suitable grafts. In 295 fibulae the foramina nutritiva and the periosteal vessels were investigated light microscopically. Moreover, by means of five amputation preparations the course of A. poplitea and its ramifications and of all nutritive vessels was shown roentgenologically and anatomically by popliteal angiography and stain injection, respectively. The foramina nutritiva were located as follows: 66.4% in the upper third, 15% in the middle, and 13.5% in the lower third of the fibula. Double foramina were noticed 10 times, no foramina 5 times. Consequences for the operative procedure are discussed.

Fibula↗