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Biomedical subjects

Y Sun

Publications and source records attributed to Y Sun.

At least 757 records · Page 42Linked to original sources
PubMed1996

[Growth regulation of human ovarian cancer cells by growth factors in vitro].

OBJECTIVE: To investigate the role of growth factors in growth regulation of human ovarian cancer cells by in vitro. METHOD: The regulation effects of different growth factors on human ovarian cancer cell line HO-8910, such as on cell proliferation, DNA synthesis, the alteration of distributions of cell phase fractions and the changes of cyclic adenosine monophosphate (cAMP) level in the presence of 2.5% fetal bovine serum (FBS) were analyzed. RESULT: (1) Insulin-like growth factor, transforming growth factor-alpha (TGF-alpha) showed weak and positive effects and were dose dependent. Epidermal growth factor (EGF) strongly stimulated cell growth and DNA synthesis in HO-8910 cells, in contrast, TGF-beta 1 inhibited cell proliferation and DNA synthesis. (2) Following the actions of various growth factors on cells in vitro, corresponding alterations in the distributions of cell phase fractions, in the formation of silver-staining nucleolar organizer regions (Ag-NORs) and in the cAMP content appeared. CONCLUSION: The growth factors exert their growth regulating effects on ovarian cancer cells through intracellular signal transduction to bring about changes in nuclear DNA synthesis and alterations in the distribution of cell phase fractions. In the process of growth regulation on ovarian cancer cells by growth factors, the change of cAMP content presents double direction regulatory function. The growth inhibitory regulation of the TGF-beta 1 possibly functions as an autocrine. This report presents evidence supporting the important roles of the growth factors and may further the study into the mechanism of growth regulation by growth factors in this cell line.

Cell Cycle↗
PubMed1996

[The ultrastructural study on radiation injuries of the jaws and soft tissues].

To search for the pathological basis of osteoradionecrosis (ORN), a ultrastructural investigation was performed on some experimental and clinical speciments. The result of this ultrastrcture study shows the nature of ORN is direct injuries of radiation rays to cells; damage of the arterioles are not the main pathologicalbasis, changes of the cytoplasm are more evident than that of nuclei. The changes of blood vessels in soft tissues are more extensive and serious than those of the bone.

Animals↗
PubMed1996

[A quantitative study on the effect of breathing exercises in improving respiratory muscle contration].

To study quantitatively the effect of breathing exercises on the prevention of progression in chronic obstructive pulmonary disease (COPD), 324 patients with stable COPD were randomly assigned to either breathing exercises (BE) or placebo medicine as control. The maximum respiratory pressure (320 cases) and transdiaphragmatic pressure (129 cases) were monitored with RMS-1 and Type-2 gastrointestinal pressure measuring instrument. BE were taught and checked by experienced specialists periodically. Patients in BE group were compared with those in the control group by measuring MIP, MEP, Pdi, and Pdimax after one to 20 months. In BE group MIP increased by 30.42%, MEP 32.10%, Pdi 30.94%, and Pdimax 65.59% (P < 0.001). No significant change was observed in the control group. MIP, MEP, Pdi, and Pdimax increased by 6.95%, 2.92%, 14.63% and 9.05% respectively (P < 0.05) in the control group. It is shown preliminarily that BE had potent and lasting effect on respiratory muscle contraction after studying large number of cases. The methods mentioned above can be used as quantitative indices for the contractile properties of respiratory muscle.

Aged↗
PubMed1996

[Preparation and characterization of human monoclonal antibody to breast carcinoma].

With fusion of human heteromyeloma cells SHM-D33 and B lymphocytes obtained from axillary lymph nodes of a patient suffering from breast carcinoma, one hybridoma cell line which secretes human monoclonal antibody CM-1 to breast carcinoma was established. The hybridoma cells have been secreting human IgM (lambda light chain) stably for over 5 years. The CM-1 concentration of the supernatant of cell culture is 38.5 micrograms per ml and is the ascites that of 2 mg per ml. The reactivity of CM-1 to normal human tissues and several kinds of tumors was examined with immunohistochemical staining. The results showed that the CM-1 reacted strongly to breast carcinoma and weakly to myxoadenocarcinoma of the esophagus. CM-1 did not react to normal tissues or other kinds of tumors, such as breast fibroadenoma, medullary carcinoma of the thyroid, etc. After injection of 131I-CM-1 into abdominal cavity of the mice bearing breast carcinoma, the image of xenografted carcinoma can be obviously distinguished from the background of normal tissues. The inhibitory effect on growth of breast cancer xenograft in nude mice was 95% for CM-1-PYM conjugate and 58% for free drug. The above results showed that the hybridom cell line CM-1 stably secreting antibody reacted specificaly with breast carcinoma and it might be useful as a drug carrier in therapy of patients with breast carcinoma.

Animals↗
PubMed1996

[Possible mechanisms for reduced endothelium dependent responsiveness to norepinephrine in isolated aorta of rats with peritonitis shock].

Various antagonists were used to analyze the possible factors contributing to the reduced endothelium-dependent response to norepinephrine in isolated aorta of rats with peritonitis shock. The concentration-effect curves to norepinephrine in the aortic rings with endothelium pretreated by methyl blue, atropine, anisodamine and indomethacin were shift to the left and the largest contraction was raised. The concentration-effect curve to norepinephrine was also shift to the left and the largest contraction was raised in the aortic ring with endothelium pretreated by propranolol. However, the similar changes were also observed in rings without endothelium pretreated by propranolol. While the concentration-effect curves to norepinephrine were shift to the right and the largest contraction reduced in rings with or without endothelium that pretreated by Yohimbine. The results suggested that the reduced endothelium-dependent responsiveness to norepinephrine in the isolated aorta of rats with peritonitis shock may involve various factors of which vasodilatation mediated by cGMP may be the one of importance.

Animals↗
PubMed1996

[The technique for extracting liposoluble components of Salvia miltiorrniza].

To investigate a reasonable producting technique for extracting the liposoluble components of Salvia miltiorrhiza, we made an orthogonal test on percolate technique of tanshinones. The results show that the concentration of alcohol has a highly remarkable influence on the extracting ratio of extract and tanshinones, where 65% alcohol is much better than higher concentration alcohol in percolate technique of tanshinones. This new technique can be employed to reduce sharply the cost and increase the extracting ratio.

Abietanes↗
PubMed1996

[Effect of human inhibin alpha-fragments and monoaminergic neurotransmitters on progesterone(P4) production by corpus luteum(CL) of rat in vitro].

The effects of exogenenous monoaminergic neurotransmitters (norepinephrine, NE; epinephrine, E; dopamine, DA and 5-HT) and inhibin alpha N-terminal fragments P32 (1-32), P32-Tyr on P4 production by incubated rat CL cells were studied. The results demonstrated that: (1) alpha fragments caused significant inhibition on P4 production. (2) 0.1 mmol/L NE (or E) and 10 mumol/L DA produced a marked increase in both basal and hCG induced P4 production by CL cells (P < 0.001). The rank orders of potency of the catecholamines in stimulating P4 production were different, for basal P4 production, NE > E > DA; but for hCG induced P4 production, DA > E > NE, i.e. the order just reversed. Addition of P32-Tyr significantly neutrolized the stimulatory action of E, but only slightly increased the action of NE. (3) alpha receptor blocker phentolamine and beta receptor blocker propranolol were effective in decreasing basal and hCG-induced P4 production, the latter being more effective than the former. It was further shown that both blockers augmented the inhibitory effect of alpha-fragments on P4 production. (4) Unlike NE, E, and DA, 5-HT at 0.5 mumol/L exerted inhibitory effect on the basal and hCG-induced P4 production, but profoundly supressed the inhibitory effect of alpha-fragments on P4 production. The above results suggested: (1) Adrenergic, DA and 5-HT receptors are present in rat CL, where catecholamine might exert a stimulating effect on basal and hCG-induced P4 production via different pathways. (2) The inhibitory effect of P32, P32-Tyr on P4 production might be related to their inhibition by partial blocking alpha/beta receptors, which were antagnized by 5-HT. (3) The action of P32, P32-TYr on P4 production is brought on the participation of neurotransmitters NE, E, DA and 5-HT.

Adrenergic alpha-Agonists↗
PubMed1996

[Hepatic tuberculosis: a report of 8 patients].

8 patients with hepatic tuberculosis were confirmed by surgical operation and pathological examination of liver. The average age of the patients was 26.5 years. Only one of the 8 patients was suspected of having hepatic tuberculosis before operation. Liver biopsy during the operation was carried out in 3 patients, and lobectomy or partial excision of the liver was performed in 4 patients, and incision and drainage of the liver abscess were performed in 1 patient. All of the patients were cured. The follow-up results showed that hepatic tuberculosis less than or equals to 3 cm in diameter could be cured by regular chemotherapeutics. In this paper, the infectious path, pathological types, differential diagnosis and treatment are discussed, and experience and lessons are summarized.

Adolescent↗
PubMed1996

[Alveolar reconstruction in patients with cleft palate].

Repair of the alveolar cleft is one important procedure in team approach of cleft palate. The present paper reports 110 cases repaired by bone grafting. Indications, technique, results evaluation and management before and after operation are discussed. The study proves that bone grafting is effective to repair alveolar cleft and should be popularised. Properly forming the bed of bone grafting and perfectly closing the receipt site are the keys of success. Patients should be treated orthodontically before and after operation. In selection of donor site, the patient's age, tooth age, width of cleft and quantity of bone to be grafted should be considered.

Adolescent↗
PubMed1996

[A new speech training method for patients following cleft palate repair].

A new method of speech training in Chinese was established according to investigations of articulatory phonetics and speech pathology of 50 patients following cleft palate operations. All of these patients were examined thoroughly and were considered to have good velopharyngal function. However, in all of them, the articulation score was lower than 70%. 33 of these 50 patients were treated with the method for a period of 22 to 120 days (average 63 days). Results showed that their articulation improved from 38.4% to 89.5% on average, the improvement in speech was highly significant statistically (P < 0.0001). In addition, the question of correct timing for speech therapy is discussed.

Adolescent↗
PubMed1996

[Study of HPV in oral squamous cell carcinoma].

In order to demonstrate the presence of human papillomavirus (HPV) in oral squamous cell carcinoma (OSCC), we detected HPV 16 and 18 type DNA in OSCC and normal mucosa (NOM) by polymerase chain reaction (PCR), then analysed the PCR products using southern blot hybridization. The study shows that the positive rates of HPV DNA were 47.8% (11/23) in OSCC, including HPV16 in 6 samples, HPV18 in 3 samples and 16, 18 co-infection in 2 samples. In contrast, HPV16 DNA were found to be 20% (2/10) in NOM. The results suggest that HPV may play a role in carcinogenesis of OSCC.

Carcinoma, Squamous Cell↗
PubMed1996

[Prevention from secondary nerve root adhesion: an experimental study].

In the study, 27 dogs were divided into three groups: A, B and C. Then all of the dogs had their lumbar intervertebral disks removed. Into the wounded cavity of group A, 1 ml of dimethicone was dropped and gelatin sponge was applied on the surface of the nerve root of group B. Group C was served as the control. The dogs were killed and the operation area was removed respectively 2 weeks, 4 weeks, and 12 weeks after the operation for macroscopical observation, nerve root motility measurement and histological examination. The result of the experiment proved that dimethicone was fairly effective in the prevention from secondary nerve root adhesion. While gelatin sponge in the process of its absorption induced the formation of quite a few scar tissues, thus aggrevating nerve root adhesion.

Animals↗
PubMed1996

[A comparative study of ethylene oxide and ionizing radiation for sterilizing bone grafts].

To find a good way for sterilization and disinfection of bone grafts, we compared the sterilization capacity of gaseous ethylene oxide (EO) and cobalt-60 gamma radiation. The bone chips were contaminated with 10(7) bacteria per milliliter of Staphylococcus aureus ATCC 25923, Bacillus subtilis globigii 8017 and Bacillus cereus 4001, then sterilized with various doses of gaseous EO or cobalt- 60 gamma radiation. The sterilization effect of EO was more stronger and faster than that of 60Co gamma radiation. The application of moderate doses of EO for sterilizing particulate bone grafts was recommended.

Animals↗
PubMed1996

[The cochlea in short-term culture].

In order to establish organotypic culture of the cochlea, the dissection of the early postnatal mouse cochlea and its morphology in short-term culture were investigated. The viability of hair cells in the culture was assessed using differential interference contrast (DIC) microscopy and double-staining with fluorescein diacetate (FDA) and propidium iodide (PI). The hair cells remained viable and did not show any signs of damage for up to 8-18 hours. When incubated in Hank's solution containing 1 mmol/L dihydrostreptomycin, the hair cells initially deteriorated in 0.5-4.5 hours and progressed to entire degeneration after 10-20 hours. In addition to its utilization in organotypic culture, the cochlea in short-term culture can be used as a valuable model for studying cellular and molecular neurobiology of the inner ears.

Animals↗
PubMed1995

Chronic exposure to retroviral vector encoded MGDF (mpl-ligand) induces lineage-specific growth and differentiation of megakaryocytes in mice.

Megakaryocyte growth and development factor (MGDF) has recently been identified as a ligand for the c-mpl receptor. Using retroviral-mediated gene transfer, MGDF has been overexpressed in mice to evaluate the systematic effects due to chronic exposure to this growth factor. MGDF overexpressing mice had more rapid platelet recovery than control mice after transplantation. Following this recovery, the platelet levels continued increasing to fourfold to eightfold above normal baseline levels and remained elevated (five-fold above control mice) in these animals, which are alive and well at more than 4 months posttransplantation. Increased megakaryocyte numbers were detected in a number of organs in these mice including bone marrow, spleen, liver, and lymph nodes. Prolonged overexpression of MGDF led to decreased marrow hematopoiesis, especially erythropoiesis, with a shift to extramedullary hematopoiesis in the spleen and liver. All the MGDF overexpressing mice analyzed to date developed myelofibrosis and osteosclerosis, possibly induced by megakaryocyte and platelet produced cytokines. No significant effect on other hematopoietic lineages was seen in the MGDF overexpressing mice, showing that the stimulatory effect of MGDF in vivo is restricted to the megakaryocyte lineage.

Animals↗