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Biomedical subjects

Y Sun

Publications and source records attributed to Y Sun.

At least 739 records · Page 41Linked to original sources
PubMed1996

Study on the production of human interferon alpha-2b expressed in Escherichia coli.

The production process of human interferon alpha-2b was established in our institute. The human interferon alpha-2b was expressed in E. coli by using PL promotor. The production process consists of high cell density fermentation, refolding of the inclusion bodies, chromatography with Sephadex G-50 and DEAE, without using monocloning antibody affinity chromatography. After purification, about 500 mg of the human interferon alpha-2b was obtained from 1 kg wet cell harvested from 10 L fermentation broth. The biological activity shows 1-2 x 10(8) IU/mg protein. This production process is very simple and easy to scale-up. If this process adapted, it will save a lot of facility investment, space, and labor. Therefore, the cost will be reduced.

Chromatography, High Pressure Liquid↗
PubMed1996

Some permutation tests for survival data.

We introduce two new classes of tests for censored data. The first tests for association between survival and a covariate and the second tests for equality of survival distributions between K groups. Both tests are permutation tests based on nonparametric test statistics and, unlike the Wald test in the proportional hazards model or the log rank test, can detect alternatives of the "crossed hazards" type. The tests are simple to implement and require no theoretical analysis by the user nor an appeal to asymptotic distribution theory. Simulation results show that the tests are competitive with their classical counterparts under proportional hazards and superior under certain nonproportional hazards alternatives in both the continuous and K-sample cases. The tests are applied to data from the British Medical Research Council's fourth myelomatosis trial and from a Danish study of malignant melanoma.

Biometry↗
PubMed1996

HSP27 locus cosegregates with left ventricular mass independently of blood pressure.

Left ventricular hypertrophy remains a significant clinical problem and a predictor of fatal outcome in hypertension. Blood pressure per se and environmental modifiers including stress affect cardiac mass. Heat shock proteins are involved in the stress response as well as in the regulation of cardiac growth and cytoprotection. The present study evaluates heat shock protein 27 as a locus marker or candidate gene of cardiac hypertrophy in hypertension. The spontaneously hypertensive rat allele of heat shock protein 27 was associated with about a 6% increase in relative left ventricular weight (P = .0112) in 30 recombinant inbred strains from crosses of Brown Norway and spontaneously hypertensive rats. In 336 F2 crosses of spontaneously hypertensive and Wistar-Kyoto rats, the hypertensive allele was dominant and cosegregated with a similar 6% increase in the ratio of left ventricular weight to body weight (P = .0058) in rats fed a normal salt diet, but its contribution to left ventricular weight decreased in rats kept on a high salt diet. The contribution of the heat shock protein 27 allele was independent of blood pressure. We suggest that heat shock protein 27 represents a candidate gene/locus marker of cardiac hypertrophy in hypertension.

Alleles↗
PubMed1996

Changes in neuropeptide phenotype after axotomy of adult peripheral neurons and the role of leukemia inhibitory factor.

Adult peripheral neurons undergo dramatic shifts in gene expression following axotomy that are collectively referred to as the cell body reaction. Changes in neuropeptide expression are a prominent feature of these axotomized neurons. For example, while sympathetic, sensory, and motor neurons do not normally express the neuropeptides galanin and vasoactive intestinal peptide, they begin to do so within days after axotomy. In contrast, the expression of other peptides, which these neurons normally express, such as neuropeptide Y in sympathetic neurons and substance P in sensory neurons, is decreased. Recent studies in sympathetic neurons have demonstrated that leukemia inhibitory factor plays an important role in triggering these changes in neuropeptide phenotype in adult neurons. Future studies will be directed at determining to what extent LIF triggers the many other changes in gene expression after sympathetic axotomy and whether this cytokine plays a similar role in sensory and motor neurons.

Animals↗
PubMed1996

Identification of somatic hybrids between rice cultivar and wild Oryza species by RAPD.

The somatic hybrids between rice cultivar and wild Oryza species were obtained by the PEG and electrical fusion method. The somatic hybrids were identified with PAPD. It was verified that the genome of somatic hybrids contained some genomes from both parents, but they contributed unequally. In some somatic hybrids, the portion from one parent was more than the other. The relationship between somatic hybrids and their parents was analyzed based on RAPD data.

DNA↗
PubMed1996

[A randomized trial of tropisetron in the prophylaxis of nausea and vomiting induced by chemotherapy].

Thirty patients receiving cisplation or non-cisplatin (containing cyclophosphamide and adriamycin) chemotherapy were enrolled in a randomized, crossover study comparing the efficacy of single dose of Navoban (tropisetron, 5 mg) and Kytril (granisetron, 3 mg). The effective control of acute vomiting induced by cisplatin was achieved in 95.2% (20/21) of patients receiving Navoban and 90.5% (19/21) in those receiving Kytril. Complele control rate was 71.4% (15/21) in Navoban arm, and 81.0% (17/21) in Kytril arm. Total control of delayed vomiting (day 2-5) was 71.4%-90.4% in Navoban arm, while it was 66.7%-4% in Kytril arm. The effective control of vomiting induced by non-cisplatin drugs was achieved in 9/9 in both arms. It is concluded that both agents are effective in the control of vomiting induced by chemotherapy. They have identical adverse effects and are well tolerated by the patients.

Adult↗
PubMed1996

Steroid-resistant asthma immunologic characteristics.

OBJECTIVE: To investigate whether persistent T lymphocyte activation is a feature of steroid-resistant (SR) asthma and to study the inhibitory effects of dexamethasone and other immuno-inhibiting agents on PHA-induced proliferation of peripheral blood T lymphocytes from SR and steroid-sensitive (SS) asthmatics. MATERIAL AND METHODS: 15 SR and 15 SS asthmatics were studied. Serum levels of soluble interleukin-2 receptor (sIL-2R) were measured before and after prednisone therapy by an enzyme-linked immunosorbent assay. PHA-driven proliferative assay was performed to evaluate inhibition of T lymphocyte proliferation. RESULTS: Serum levels of sIL-2R were elevated in both patients with SR and SS asthma as compared with normal controls (P < 0.001). After a 7-day course of prednisone (20 mg/day), serum levels of sIL-2R decreased significantly in SS asthmatics (P < 0.001) but not in SR asthmatics (P > 0.1). Proliferation of T lymphocytes from the sensitive but not the resistant asthmatics was significantly (P < 0.002) inhibited by dexamethasone (10 mol/L), reflecting a shift of the dose-response curve. In contrast, oxymatrine and thymus-derived immunosuppressors inhibited proliferation of T lymphocytes to a similar degree between SR and SS asthmatics. CONCLUSIONS: The results suggest that persistent T lymphocyte activation due to a relative insensitivity of the cells to glucocorticoids is a feature of SR asthma. Immuno-inhibiting agents other than glucocorticoids may be of therapeutic benefit in patients with SR asthma.

Adult↗
PubMed1996

[Middle ear function in children with cleft palate].

Middle ear problems in patients with cleft palate have for a long time received insufficient attention. The present study was designed to evaluate middle ear function in 56 children with cleft palate and in a control group of 50 children without cleft palate. The age ranging between 5 and 14 years was similar in both groups. All children underwent routine otoscopic examinations of ear, nose and throat, and were also examined using the Madsen acoustic impedance audiometer. Four major parameters (static compliance, middle ear pressure, acoustic stapedius reflex and Eustachian tube function) were analyzed. It was found that the negative middle ear pressures were higher and the static compliance, which reflected the elasticity of the conducting mechanism of the middle ear, was poorer in children with cleft palate than in the controls. The proportion of children with cleft palate who showed the presence of the acoustic stapedius reflex was also lower than in the control children. Children with cleft palate have a limited ability to actively open the Eustachian tube by swallowing, as evidenced by a poor ability to equilibrate applied positive or negative middle ear pressure. A multidisciplinary approach should be adopted for the complete overall rehabilitation of children with cleft palate. Plastic surgeons to whom most of the treatment is entrusted should be concerned not only with achieving palatal function and acceptable speech, but also with the various other problems associated with cleft palate, especially those affecting the middle ear.

Abnormalities, Multiple↗
PubMed1996

Spike waves and synaptic ultrastructure in human epileptic brains.

OBJECTIVE: To find morphological changes of synapses related to the spike discharge by observation on ultrastructures of the EEG spike foci of cerebral cortexes. MATERIAL AND METHODS: The cerebral cortexes were obtained surgically from the EEG spike (recorded by flaky silver electrodes on the surface of cortexes) foci and nonspike areas within the limits of the brain tissue that would be removed in 20 cases of human epilepsy, and were processed for transmission electron microscopic (TEM) observation. RESULTS: In the spike foci, presynaptic terminals of axospinal asymmetric synapses were obviously swollen but postsynaptic spines were relatively unaffected. In these synapses, the synaptic vesicles remarkably decreased in number and accumulated predominantly at the presynaptic membranes or aggregated. Similar changes were observed in the presynaptic terminals of the axospinal asymmetric synapses in the nonspike areas but were of milder degree than in the spike foci. CONCLUSION: Axospinal asymmetric synapses may release a large quantity of excitatory neurotransmitters, which may result in epileptic abnormal electric activities during seizure.

Adolescent↗
PubMed1996

[Antimicrobial properties of Flos Lonicerae against oral pathogens].

The antimicrobial effect of Flos Lonicerae on oral pathogens was studied. The results showed that 73.9% of the tested pathogens were inhibited at a concentration below 6.25mg/ml. Streptococci mutants, actinomyces viscosus and bacteroides melaninogenicus were comparatively more sensitive to Flos Lonicerae.

Actinomyces viscosus↗
PubMed1996

[Phase I clinical study of a new anticancer drug boanmycin].

From August 1993 to March 1994, 36 patients were enrolled for a phase I study of Boanmycin (Bleomycin A6) a new anticancer drug to determine it toxicity and maximal dose. Of the 36 cases, 16 were male and 20 female, age 20-62. Dose escalation was performed if a minimum of threed patients were fully evaluable for toxicity (2 weeks following drug administration) and if severe or life-threatening toxicity had not occurred. Dose of Boanmycin were escalated from 1 mg (0.5-0.7 mg/m2) to 12 mg(6.7-7.5 mg/m2) i. m. three times every week for two weeks. Surveillance of serum concentration of Boanmycin was conducted in six cases by microbiological analysis, and the pharmacokinetics parameters were obtained. Phase I study of Boanmycin showed that Boanmycin had no myelosuppression and cardiac toxicity, and its major adverse reactions were fever, gastrointestinal reactions and hardening at injection (by i. m. route). Rather than dose-related, fever was individual-related. There were mild myalgia, alopecia, skin rash, pigmentation in some patients. All adverse reactions resolved after discontinuation of therapy. There was no Boanmycin-related lethal complication, and the maximum tolerated dose was not obtainable. If patients have renal or lung disease, Boanmycin aggravate their renal and lung functions. Therefore we recommend that dose of Boanmycin for phase I clinical trial should be is 8-10 mg(5-6 mg/m2) i m or iv (iv can decrease local side effect) two-three times per week.

Adult↗
PubMed1996

Quantitative research for improving respiratory muscle contraction by breathing exercise.

OBJECTIVE: To investigate the effects of breathing exercise on chronic obstructive pulmonary disease (COPD). PATIENTS AND METHODS: 324 patients stable COPD were randomly assigned to either the breathing exercise group (Group I) or control group consisting of placebo (Group II). The maximum respiratory pressure (320 cases) and transdiaphragmatic pressure (129 cases) were monitored via RMS-I and Type-2 pressure measurements. The breathing exercises were taught and checked by experienced specialists periodically. Comparison was made between Group I and Group II using maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), diaphragmatic pressure (Pdi) and maximum transdiaphragmatic pressure (Pdimax) after 1 to 20 months. RESULTS: In Group I MIP increased by 30.42%, MEP 32.10%, Pdi 30.94% and Pdimax 65.59% (P < 0.001). No significant changes were observed in Group II given the placebo. The MIP, MEP, Pdi and Pdimax were 6.95%, 2.92%, 14.63 and 9.05% respectively (P > 0.05). CONCLUSIONS: Breathing exercise has a potent and long lasting effect on respiratory muscle contraction. The methods mentioned above can be used as standard quantitative index for contractile properties of respiratory muscle.

Aged↗
PubMed1996

[A comparison of the changes of the nasal deformities after cleft lip repair between rotation advancement and triangular flap repair].

126 patients with the secondary nasal deformities of cleft lip were chosen at random, whose primary correction of cleft lip were performed by the same surgon. Of them, 68 patients were treated by triangular flap method, other 58 by rotation advancement method. On their photographs, two methods were compared by measurement of the distance between alar bases and median saggittal plane, the width of nostril floor, the height of the columella, the sizes of nostrils on both sides, and tilt of columella. The nasal deformities were improved in the rotation advancement group, but this method trend to result in a small nostril to make correction of secondary nasal deformities more difficult. On the other hand, the nasal defects were little improved in triangular flap group, whereas there were much less tendency to result in a small nostril.

Abnormalities, Multiple↗
PubMed1996

[Phase III clinical trial of elemenum emulsion in the management of malignant pleural and peritoneal effusions].

From July 1994 to June 1995, a prospective multicenter phase III clinical trial was conducted to evaluate the efficacy of Injectio Emulsioni Elemeni in the management of malignant effusions. Four hundred and eighty-four patients, including 313 with pleural effusion and 171 with peritoneal effusion, were evaluable. The drug was administered in 0.5% emulsion, with a dosage of 200 mg/m2 for intrapleural injection once every week for 1-2 weeks and 300-400 mg/m2 for intraperitoneal injection once or twice every week for 2 weeks. The response rates were 77.6% in patients with malignant pleural effusion, 66.1% in patients with peritoneal effusion. There were no bone marrow, liver, cardiac and renal toxicities; while fever, local pain and gastro-intestinal reaction were the major adverse effects. It is concluded that Elemenum emulsion is one of the active agents in the management of malignant effusions.

Adolescent↗
PubMed1996

[Results of phase II clinical trial of vindesine in the treatment of malignant tumors].

A phase III clinical trial of vindesine-containing regimens organized by Chinese Medical Association was conducted from November 1993 to October 1994. In 799 evaluable cases, the overall response rate was 64.5% and the individual response rate was 74.1% for SCLC, 52.6% for NSCLC, 88.0% for malignant lymphomas, 62.6% for breast cancer, 57.5% for esophageal carcinoma, 59.0% for overian carcinoma and 94.0% for ALL. There were 1532 patients evaluable for toxicity. The dose-limiting toxicity was myelosuppression. Gastro-intestinal reactions, peripheral neuritis, alopecia and phlebtitis were also common. It is concluded that vindesine is similar to that reported as to response rate and toxicity.

Adolescent↗
PubMed1996

Role of transforming growth factor beta (TGF-beta) in repairing of bone defects.

TGF-beta is a multifunctional cytokine that regulates many aspects of cellular function, including periosteal mesenchymal cell proliferation, differentiation. This experiment is to study its effects on bone defect repair. A rabbit radial bone defect model was used to evaluate the effect of TGF-beta, which was extracted and purified from bovine blood platelets, on the healing of a large segmental osteoperiosteal defect. A 1.5-centimeter segmental defect was created in the mid-upper part of the radial shaft of adult rabbits. The defect was filled with implant containing TGF-beta that consisted of carrier and bovine TGF-beta. Limbs served as controls received carrier alone. The defects were examined radiographically and histologically at 4, 8, 12, 16 and 20 weeks after implantation. The results showed that in TGF-beta implant group, the defect areas at 12 weeks post operation were bridged by uniform new bone and the cut ends of cortex could not be seen; while in control group, the defects remained clear. Only a small amount of new bone formed as a cap on the cut bone ends. In the experimental group, new lamellar and woven bone formed in continuity with the cut ends of the cortex. An early medullar canal appears to be forming and contained normal-appearancing marrow elements; while the control group displayed entirely fibrous tissue within the defect site. Remnants of the cancellous bone carrier were observed in the control specimen. These data demonstrate that exogenous TGF-beta initiate osteogenesis and stimulate the bone defects repair in animal model.

Animals↗