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Biomedical subjects

Y Cai

Publications and source records attributed to Y Cai.

At least 55 records · Page 3Linked to original sources
PubMed2001

A new sesquiterpene lactone from Tsoongiodendron odorum Chun.

A new sesquiterpene lactone (1) was obtained from the cytotoxic fraction of 95% ethanol extract of root barks of Tsoongiodendron odorum Chun together with two known sesquiterpene lactones, costunolide (2) and parthenolide (3). The structure of 1 was elucidated as 5alpha, 6alpha, 7beta, 10beta- 11alpha, 13-dihydro-4(15)-eudesmene-12, 6-olide on the basis of chemical and spectral evidence including X-ray diffraction analysis. Costunolide showed cytotoxic activity against human leukemia (HL-60) cell line. Parthenolide showed promising cytotoxic activities in vitro against HCT-8, Bel-7402, SKOV3, KB, HELA and EJ cell lines. Also, the cytotoxic ethyl acetate fraction of ethanol extract of the root barks from which three chemical components were isolated showed promising cytotoxic activities in vitro against KB, BGC-823, Bel-7402, HCT-8, HL-60 cell lines.

Antineoplastic Agents, Phytogenic↗
PubMed2001

Renal tubular dysfunction in male inhabitants of a cadmium-polluted area in Toyama, Japan--an eleven-year follow-up study.

An eleven-year follow-up study was carried out to elucidate the changes in the level of environmental exposure to cadmium (Cd) from rice after soil replacement of polluted paddy fields and these effects on urinary excretion of Cd in male inhabitants of a Cd-polluted area in Toyama, Japan. In addition, the prevalence of renal tubular dysfunction (RTD) was examined to clarify the progress of Cd-induced RTD. One hundred and twenty-seven male inhabitants born between 1914 and 1929 in 11 districts of the Cd-polluted Jinzu River basin and 31 reference subjects in 2 adjacent districts were examined twice in 1985-86 and 1996-97. The geometric means of Cd concentrations in polished rice (Cd-R) in the Cd-polluted areas were 0.18 ppm in 1985 and 0.21 ppm in 1986; these values were significantly higher than those of the reference areas (0.13 ppm in 1985 and 0.12 ppm in 1986). After 11 years, the Cd-R levels were significantly decreased to approximately half (0.08 ppm in 1996, 0.12 ppm in 1997) due to soil replacement of polluted paddy fields, which has been carried out since 1980. The mean Cd levels in urine (Cd-U) were significantly reduced from 7.9 and 9.5 microg/g creatinine in the initial study to 6.9 and 6.8 microg/g creatinine in the follow-up study. However, the prevalence of RTD, which was determined by urinary beta2-microglobulin exceeding 1 mg/g creatinine and urinary glucose exceeding 150 mg/g creatinine, increased from 18 and 23% in the 1985-86 study to 25 and 32% in the 1996-97 study, and a total of 12 new cases (12%) of RTD were found. Whereas, only one subject (4%) in the reference control areas was identified as RTD. Cd-induced RTD was prevalent, progressive and irreversible for male inhabitants of the Cd-polluted Jinzu River basin, although the environmental exposure to Cd through rice was significantly reduced by soil replacement of polluted paddy fields.

Aged↗
PubMed2001

Effect of benzene, toluene, xylene on the semen quality and the function of accessory gonad of exposed workers.

The effects on semen and the function of accessory gonad of workers after short and long term exposure to benzene, toluene, and xylene were examined. The semen and blood of 24 married workers exposed to benzene, toluene, and xylene were collected. Routine sperm characteristic, acrosin activity, and Lactate dehydrogenase C4 (LDH-C4) relative activity were detected. The results showed that benzene, toluene, and xylene were found in the blood and semen of some ex-workers at workplaces where the air concentration of benzene, toluene, and xylene exceeded the maximum allowable concentration (MAC). No such solvents were detected in the blood and semen of workers of the control group. The sperm vitality and sperm motility decreased in the exposed workers. The mean acrosin activity, gamma-GT activity and LDH-C4 relative activity in the exposed workers were lower, and fructose concentration was higher than those in the control. There were negative correlations between sperm vitality, sperm activity, acrosin activity, or LDH-C4 relative activity and working history. These results suggest that the mixture of these solvents could affect the sperm and the function of accessory gonad. This might be one reason of the abnormal pregnancy outcome among the wives of workers exposed to benzene, toluene, and xylene.

Acrosin↗
PubMed2001

Phase I pharmacokinetic study of tea polyphenols following single-dose administration of epigallocatechin gallate and polyphenon E.

Green tea has been shown to exhibit cancer-preventive activities in preclinical studies. Its principal active components include epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin (EC), and epicatechin gallate, of which EGCG is the most abundant and possesses the most potent antioxidative activity. We performed a Phase I pharmacokinetic study to determine the systemic availability of green tea catechins after single oral dose administration of EGCG and Polyphenon E (decaffeinated green tea catechin mixture). Twenty healthy subjects (five subjects/dose level) were randomly assigned to one of the dose levels (200, 400, 600, and 800 mg based on EGCG content). All subjects were randomly crossed-over to receive the two catechin formulations at the same dose level. Blood and urine samples were collected for up to 24 h after oral administration of the study medication. Tea catechin concentrations in plasma and urine samples were determined using high-performance liquid chromatography with the coulometric electrode array detection system. After EGCG versus Polyphenon E administration, the mean area under the plasma concentration-time curves (AUC) of unchanged EGCG were 22.5 versus 21.9, 35.4 versus 52.2, 101.9 versus 79.7, and 167.1 versus 161.4 min x microg/ml at the 200-, 400-, 600-, and 800-mg dose levels, respectively. EGC and EC were not detected in plasma after EGCG administration and were present at low/undetectable levels after Polyphenon E administration. High concentrations of EGC and EC glucuronide/sulfate conjugates were found in plasma and urine samples after Polyphenon E administration. There were no significant differences in the pharmacokinetic characteristics of EGCG between the two study medications. The AUC and maximum plasma concentration (Cmax) of EGCG after the 800-mg dose of EGCG were found to be significantly higher than those after the 200- and 400-mg dose. The AUC and Cmax of EGCG after the 800-mg dose of Polyphenon E were significantly higher than those after the three lower doses. We conclude that the two catechin formulations resulted in similar plasma EGCG levels. EGC and EC were present in the body after the Polyphenon E administration; however, they were present predominantly in conjugated forms. The systemic availability of EGCG increased at higher doses, possibly due to saturable presystemic elimination of orally administered green tea polyphenols.

Administration, Oral↗
PubMed2001

[Corrosion and haemocompatibility of 316L stainless steel with electroplated Rh film].

In this study, surface modification by electroplating Rh on 316L stainless steel was carried out in order to improve the corrosion resistance and blood compatibility of implants. XPS was used to characterize the Rh film. The corrosion behavior of 316L stainless steel with electroplated Rh and non-treated was studied in Tyrode's biological solution. Additionally, the haemocompatibility of 316L stainless steel with electroplated Rh was evaluated by preliminary hemolysis test. The results showed that the corrosion resistance of 316L stainless steel with electroplated Rh was improved, and hemolysis decreased, which indicated that electroplating Rh can improve the blood compatibility of 316L stainless steel.

Animals↗
PubMed2001

[The use of limit amplitude technique in clinical cardiac electrical signal recording].

Based on the electrophysiologic mechanism of cardiac electrical action and the theory of voltage effect, the limit amplitude technique was employed to obtain the best clinical record effects. The results showed that limiter could limit the oversize signals overlapping each other and make the tiny signals magnification without distortion, such as the His bundle deflection in His Bundel Electrogram. At the same time, all signals recorded at multichannel physiologic recorder were clear and did not interfere with each other. Furthermore, the limiter not only improved the recording quality but also protected the cardiac electronic equipment because overdue stimulation signal was limited at a given electronic level during the recording of transesophageal pacing.

Electrocardiography↗
PubMed2001

[The effects of Polyrhachis vicina on immunoregulation in mice].

OBJECTIVE: To study the immuno-regulatory effects of Polyrhachis vicina Roger(PVR) in mice. METHOD: By determining the immune function of normal mice and immune function-depressed or enhanced mice after the administration of PVR. RESULTS: PVR (0.25 g.kg-1.d-1 x 10 d, 0.5 g.kg-1.d-1 x 10 d, 1.5 g.kg-1.d-1 x 10 d, op) had no effects on non-specific immune function (weight of immune organs) and cell immune function (delayed type hypersensitivity, DTH) in normal mice, but could improve the non-specific immune function and fluids immune function (hemolysin assay method) in immune function-depressed mice induced with hydrocortisonun (5 x 10(-2) g.kg-1.d-1 x 5 d). Both depressed DTH and enhanced DTH induced with cyclophosphamide (Cy) at the doses of 80 mg.kg-1.d-1 x 1 d and 250 g.kg-1.d-1 x 10 d ig. respectively were regulated by PVR (1.5 g.kg-1.d-1 x 10 d). CONCLUSION: PVR has immuno-regulatory activities in mice.

Adjuvants, Immunologic↗
PubMed2001

Estimation of the radionuclide distribution in sediment in coast area.

The study of the radionuclide distribution in sediment is a very important aspect in environmental impact of the low level radioactive liquid waste (LLW) from coastal nuclear facilities or nuclear power plant. Even now we do not know much about it. In this paper, a simple and useful method is put forward and it is used to estimate the nuclide distribution in sediment. The result showed that the LLW from nuclear facility or nuclear power plant will do a little harm to the sediment nearby. But the harm is not very serious. Much works have to be done before full understanding of the situation.

Environmental Monitoring↗
PubMed2001

[A study on effect of basic fibroblast growth factor on human limbal stem cell proliferation cultured in low calcium medium].

OBJECTIVE: To study how to obtain relatively pure stem cells and the effects of bFGF on the human limbal stem cell proliferation in order to set up the foundation of cultured limbal stem cells for treatment of ocular surface and tear diseases. METHODS: Limbal button inoculation was used in low calcium culture. Monoclonal antibody AE5 was used to identify the stem cells. To examine the effects of bFGF (1 - 100 ng/ml) on stem cell proliferation, the technique of digital camera and computer image analysis system were used. RESULTS: Cultured cells were mostly corneal stem cells. This was the first time to combine the method of obtaining basal cell layer and culture with low calcium medium, which could harvest relatively pure and undifferentiated stem cells in localization and nature. The basic FGF (1 - 100 ng/ml) promoted cultured stem cells to proliferate significantly (P < 0.001). CONCLUSIONS: Limbal stem culture provides resources of stem cells. It is very useful in treatment of ocular surface and tear diseases. The basic FGF plays an important role in proliferation of stem cells in graft. Computer image analysis system is an effective and simple way for evaluating the proliferation of a primary culture.

Calcium↗
PubMed2001

Effect of O6-benzylguanine on nitrogen mustard-induced toxicity, apoptosis, and mutagenicity in Chinese hamster ovary cells.

O6-Benzylguanine (BG) inactivates O6-alkylguanine-DNA alkyltransferase (AGT), resulting in an increase in the sensitivity of cells to the toxic effects of O6-alkylating agents. BG significantly enhances the cytotoxicity and decreases the mutagenicity of nitrogen mustards [i.e., phosphoramide mustard (PM), melphalan, and chlorambucil], a group of alkylating agents not known to produce O6-adducts in DNA. The enhancement is observed in cells irrespective of AGT activity. Exposure of Chinese hamster ovary cells to 100 microM BG results in enhancement in the cytotoxicity of PM (300 microM), chlorambucil (40 microM), and melphalan (10 microM) by 9-, 7-, and 18-fold, respectively. In contrast, mutation frequency after treatment with 300 microM PM is decreased from 259 mutants/10(6) cells to 22 mutants/10(6) cells when cells are pretreated with BG. The enhancement of toxicity of these bis-alkylating agents appears to involve cross-link formation, because neither cytotoxicity nor mutagenicity of a monoalkylating PM analogue is significantly altered when combined with BG. Enhanced cytotoxicity and decreased mutagenicity is concomitant with a dramatic increase in the number of cells undergoing apoptosis when BG is combined with PM, melphalan, or chlorambucil at 72-94 h after treatment. Cell cycle analysis demonstrates that BG alone or combined with nitrogen mustards arrests cells in G1 phase of the cell cycle. At 16 h after treatment, 11 and 57% of cells treated with PM alone or with BG plus PM are in G1 phase, respectively. Our data suggest that treatment with BG causes G1 arrest and drives noncycling cells treated with nitrogen mustards into apoptosis, thus protecting against mutagenic DNA damage introduced by nitrogen mustards.

Animals↗
PubMed2001

[Diagnostic significance of audiological and vestibular function examination in the pontocerebellar angle tumor].

OBJECTIVE: To study the diagnostic value of audiological and vestibular function examination in the pontocerebellar angle tumor. METHOD: The data of audiological and vestibular function test were analized retrospectively in 20 subjects with tumors of the pontocerebellar angle. RESULT: Pure tone and ABR waveforms were abnormal in 20 subjects (21 ears), moreover acoustic stapedius reflex and the vestibular function were abnormal in 19 subjects. CONCLUSION: It's valuable that audiological and vestibular function examinations are able to diagnosis the pontocerebellar angle tumor.

Adult↗
PubMed2001

[Analysis on the surveillanca data of newborn death from 1990 to 1999 in Rugao City, Jiangsu province].

A surveillance and data analysis on the cause and death rate of newborn death in Rugao city, Jiangsu Provinces was conducted from 1990 to 1999. There were 1300 cases died in these 10 years. The mortality rate was 0.92% and the proportion of male to female was 1.53:1. More cases (75%) were died in the early stage after birth. The causes of the newborn death were in the order of premature, asphyxia, pneumonia, congenital anomaly and accidental asphyxia. More babies (75.62%) were died in hospitals. The emphasis on newborn health care was pointed out and had discussions. Taking comprehensive measures would be the key point to reduce newborn mortality rate.

Asphyxia Neonatorum↗
PubMed2001

[Effect of "yang wei kang liu" granula on expression of P53 and PCNA in mice bearing sarcoma 180].

OBJECTIVE: To study possible mechanism of "Yang Wei Kang Liu" (YWKL) granula in treating tumor. METHODS: Mice bearing sarcoma180 and immunohisto-chemical method were adopted. RESULTS: Both YWKL granula and its cooperated chemothrapy could restrain the expression of P53 and PCNA. Compared with the chemotherapy group and the cooperated chemotherapy, YWKL granula group was significantly different. CONCLUSION: YWKL granula could restrain the expression of P53 and PCNA, and increase the effect together with chemotherapy.

Animals↗
PubMed2001

[A multi-centered clinical study an domestic intravenous Turbutalin sulfate in the treatment of asthma and chronic asthmatic bronchitis].

OBJECTIVE: This multi-centered clinical trial was designed to assess the efficacy and safety of domestic intravenous Turbutalin Sulfate in the treatment of asthma and chronic asthmatic bronchitis. METHODS: Bricanyl was used as control. A total of 120 patients were included in this randomized controlled study. The two medications, both at a dose of 0.25 mg intravenous drip, were given three times a day for 3-5 days. RESULTS: The two drugs' clinical excellent rates were 66.7% and 73.3%; overall efficacy rates were 98.3% and 100.0%, respectively. Their pulmonary functional excellent rates were 78.4% and 76.6%; overall effect rates were 88.3% and 90.0%, respectively. Composite curative evaluation showed that the two drug's composite excellent rates were 61.6% both; their overall efficacy rates were 88.3% and 90.0%, respectively. All of these showed no significant difference (P > 0.05). The incidence rates of adverse side effects of the two groups were 13.5% and 15.0%, respectively; most of them were mild and tolerable. CONCLUSION: Domestic intravenous Terbutalin Sulfate is effective and safe in treating asthma and chronic asthmatic bronchitis.

Adolescent↗
PubMed2001

Expression and deletion analysis of EcoRII endonuclease and methylase gene.

OBJECTIVE: To clone complete EcoRII restriction endonuclease gene (ecoRIIR) and methyltransferase gene (ecoRIIM) in one vector and to analyze the coordinating expression of this whole R-M system. METHODS: Unidirectional deletion subclones were constructed with ExoIII. ecoRIIR/ M genes were preliminarily located in the cloned fragment according to the enzyme activities of subclones. Exact deletion sites were determined by sequencing, and transcriptional start sites were determined by S1 mapping. RESULTS: The DNA fragment which was cloned into pBluescript SK + contained intact ecoRIIR gene and ecoRIIM gene, and two transcriptional start sites of ecoRIIR gene were determined. 132bp to 458bp from 3'end of ecoRIIR gene are indispensable to enzyme activities and deletion of 202bp from 3' end of ecoRIIM gene made enzyme lose the capability in DNA protection to resist specific cut with EcoRII endonuclease (EcoRII. R). Deletion of the coding and flanking sequences of one gene did not affect the expression of the other gene, and the recombinants only containing ecoRIIR gene appeared to be lethal to dcm+ host. CONCLUSION: ecoRIIM gene linking closely to ecoRIIR gene is very important for the existence of the R-M system in process of evolution, but the key to control EcoRII R-M order may not exist in transcriptional level .

Base Sequence↗
PubMed2001

[Determination of the binding site of testis-specific nucleoporin BS-63 to transportin (karopherin beta 2) and the proof of their combination in vitro].

OBJECTIVE: To locate the binding site of testis-specific nucleoporin BS-63 to transportin (karopherin beta 2) and confirm their combination in vitro. METHODS: Constructed different fragments of C terminal BS-63 was employed to localize the binding site of the testis-specific nucleoporin BS-63 to transportin by yeast two-hybrid system technique pull-down test was used to identify the interaction between the purified expressed fragments of BS-63 0.6 K and transportin in vitro. RESULTS: BS-63 binding site to transportin was shortened from 1.6 kb to 0.6 kb which included a Ran binding domain (RanBD). SDS-PAGE and Western blot tests confirmed the recombinant purified protein coded by 0.6 kb fragment of BS-63 cDNA could interact with transportin in vitro. CONCLUSIONS: In germ cells, the function of the testis-specific nucleoporin BS-63 localized at cytoplasmic side of NPC importing cargoes into nuclear may be accomplished by transportin cooperation.

Binding Sites↗