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Biomedical subjects

Z Li

Publications and source records attributed to Z Li.

At least 361 records · Page 20Linked to original sources
PubMed2001

[Preliminary study on the rules of streptococcus mutans reactive oxygen species metabolism].

OBJECTIVE: To study the rules of Streptococcus mutans reactive oxygen species metabolism and its enzymatic basis, and to investigate its significance intermediate to plaque microbial ecology. METHODS: Electron spin trapping method was used to measure reactive oxygen species produced by Streptococcus mutans in the different incubation conditions, and evaluate the efficicay of NADH to hypoxanthine-xanthine oxidase and Fe(2+)-H2O2 system. RESULTS: Electron spin resonance (ESR) spectrum of DMPO-O2- and DMPO-OH. and superoxide dismutase were obtained in Streptococcus mutans culture fluid, these spectrum were strengthened by exogenous sugar, and disappeared when methylene blue was added to culture fluid, but that spectrum was not significantly changed by NADH. ESR spectrum of hypoxanthine-xanthine oxidase and Fe(2+)-H2O2 system were significantly reduced or disappeared by NADH. CONCLUSION: These results suggest that there are O2- and OH in Streptococcus mutans metabolism, and they may come mainly from the reaction catalyzed by NADH oxidase.

Electron Spin Resonance Spectroscopy↗
PubMed2001

[Clinico-pathological significance of microvessel density and vascular endothelial growth factor expression in adenoid cystic carcinoma of salivary glands].

OBJECTIVE: To evaluate the clinical significance of microvessel density(MVD) and vascular endothelial growth factor(VEGF) expression in adenoid cystic carcinoma of salivary glands. METHODS: Immunohistochemical staining(SP) was used to quantify MVD and VEGF expression in specimens from 55 patients with adenoid cystic carcinoma of salivary glands. SPSS statistical software was used. RESULTS: High VEGF expression was correlated with tumor site and stage (P = 0.0398, P = 0.0175), but not with local recurrence, distant metastasis, regional lymph node metastasis, histological classification and survival rate. A significant correlation was not noted between MVD and the above variables. The mean MVD in cases of high VEGF expression was significantly higher than those in cases of low VEGF expression (P = 0.0202). CONCLUSIONS: In adenoid cystic carcinoma of salivary glands, MVD and VEGF may be served as a prognostic factor which needs further study, but there is a significant positive correlation between MVD and VEGF expression.

Adult↗
PubMed2001

[Combined construction of rainwater catchment techniques with methane pool and greenhouse].

A combined structure of rainwater catchment, methane pool and reformed greenhouse was constructed to improve water use efficiency. The results showed that the combination of rainwater catchment, reserving techniques and water saving measures was efficient to resolve the problem of water deficiency in the semi-arid region with precipitation of 250-550 mm. The combined structure of water catchment engineering, greenhouse and methane pool redistributed light, temperature, water and heat to develop higher benefits economic crops, and improved water use efficiency, which made it possible to develop high yield, and best quality agriculture in this region. Through optimizing the ecological factor in greenhouse, the water use was reduced by 50%-70%, and the soil temperature and night temperature were raised. This combined construction also improved productivity in greenhouse, and efficiently controlled plant diseases and insect pests. Methane pool provided CO2 and part energy source. The shady area back of the greenhouse was exploited by growing shady crops and epiphyte, which contributed to exchange energy and CO2 between light and shady house. This model could be used as water catchment agricultural development model in the region, and some other new approaches to water catchment agriculture in semi-arid region were discussed in this paper.

Agriculture↗
PubMed2001

[Intrauterine growth retardation and cerebral palsy].

OBJECTIVE: To obtain the prevalence of cerebral palsy in children affected with intrauterine growth retardation (IUGR) and to explore the association between IUGR and cerebral palsy. METHODS: A cross-sectional survey was carried out among children aged under 7 years in seven cities of south Jiangsu Province. RESULTS: There were 5.6% (95% CI 5.6% to 5.7%) of the children classified as IUGR with a bimodal distribution, the highest in the 35-36 and 42-43 weeks of gestational age. The prevalence of cerebral palsy (CP) in IUGR children was 5.7@1000 (95% CI of 4.7@1000 to 6.9@1000), 4.2 times more than that in non-IUGR children (95% CI of 3.4-5.2). The prevalence of CP in IUGR children of preterm and term delivery (< 37 weeks and > or = 37 weeks of gestational age) was 1.9 (95% CI of 1.2 to 3.0) and 4.2 (95% CI of 3.3 to 5.3) times more than that in non-IUGR children, respectively. Multiple logistic regression analysis showed the effect of IUGR on CP for children with birth weight greater than 2,500 g, after controlling for birth weight and gestational age. CP prevalence in IUGR children was two times more than that in non-IUGR children. Furthermore, prevalence of IUGR in children with birth weight lower than the 3rd percentile and in those with the 3rd percentile to lower than the 10th percentile was 3.4 and 1.8 times more than that in non-IUGR children, respectively. CONCLUSIONS: The prevalence of cerebral palsy in IUGR children was 5.7@1000, 4.2 times that in non-IUGR children and IUGR is an independent risk factor for cerebral palsy.

Birth Weight↗
PubMed2001

[An exponential universal formula and evaluation model of sustainable development for cities].

In order to study an evaluation model of sustainable development for cities, analysis was performed to study the features of indicator system of community, economy and environment. Based on the genetic algorithms optimum, an exponential universal formula of single indicator was proposed. Evaluation model of sustainable development about the coordinative development of community, economy and environment was developed using weighting method combining the general contrast algorithm with analytic hierarchy process for different structure. The evaluation results of sustainable development for examples using this model showed that the exponential formula of single indicator based on parameters optimum and the evaluation model are not only simple and practical, but also comparisonable, realizable and general.

City Planning↗
PubMed2001

[Treatment of 2-naphtholwastewater using air oxidation and ion exchange].

The properties of 2-naphtholwastewater were studied in details in this paper, the wastewater was characterized by the strong acidity, high buffer capability and concentrated salt. Air oxidation and anion exchange were employed for the treatment of the wastewater. Under formal pH, room temperature and 1 BV/h rate, the result showed that the removal of COD reached to 97% and the recovery of sodium naphthalensulfonate to 98%. Besides, wastewater treated can be reused for washing the sodium naphthalensulfonate.

Alkalies↗
PubMed2001

[Extraction and stripping of H acid and DSD acid wastewater].

H acid and DSD acid are two important substrate of dyes, which wastewater is treated more difficulty because of containing multi-component, with high chroma value and nonbiodegradability. A treatment way of this wastewater by extraction based on chemical association was carried out. Trialkylamine (Alamine 336) and chlorinated quaternary ammonium salt (Aliquat 336) were used as reacting agent with n-octanol, kerosene as modifier and diluent respectively. Results showed that the extraction efficiency depended on solution pH. Alamine 336 could be used to treat waste water with low pH while Aliquat 336 was high efficiency for waste water with pH > 6. Recovery yield of H acid and DSD acid was greater than 99% and the chroma value of wastewater was reduced effectively by simulating multi-stages cross-flow extraction. Back-extraction is quite easy and the solvent could be regenerated.

1-Octanol↗
PubMed2001

[Implanted percutaneous continuous hepatic arterial infusion system for nonresectable liver metastasis].

OBJECTIVE: To evaluate the efficacy of continuous hepatic arterial infusion of 5-fluorouracil (5-Fu)/calcium folinate (CF) through an implanted percutaneous arterial infusion system for nonresectable liver metastasis. METHODS: Sixty-eight patients with nonresectable liver metastasis received continuous hepatic arterial infusion of 5-Fu 500 mg/m2.d, CF 100 mg/m2.d and dexamethasone 10 mg/d1-5 via a drug delivery system (DDS) implanted percutaneously with the catheter introduced via the femoral artery or left subclavian artery for 5 days, once every month in combination with cisplatin and/or mitomycin-C, epirubicin and cytoxan as a multi-drug protocol. RESULTS: The overall response rate (CR + PR) was 47.1% (32/68), with 2 patients giving CR and 30 PR. The response seemed to correlate with the intrahepatic tumor burden as 60.6% response rate was observed in intrahepatic tumor burden of less than 25% versus 34.3% response rate in those with more than 25% (P < 0.05). The median survival period was 15.2 months. The 1-, 2-year survival rates were 61.1% and 35.2% respectively in 54 patients who were followed. The therapeutic result was better in patients with liver metastasis originating from the gastrointestinal tract carcinoma than those from non-gastrointestinal tract carcinoma (P < 0.05). In patients with liver metastasis originating from the gastrointestinal tract carcinoma, the median survival was 17.6 months, with 1-, 2-year survival rates of 68.4% and 39.5%. There was no severe toxic side effects or complications. The toxic reaction in liver, biliary and gastrointestinal tract was mild. CONCLUSION: Continuous hepatic arterial infusion of 5-Fu/CF and dexamethasone via a subcutaneous drug delivery system is able to prolong the survival and improve the quality of life in patients with nonresectable liver metastasis.

Adult↗
PubMed2001

[Immunogenicity and safety of recombinant yeast-derived hepatitis B vaccine (YDV) on adults].

OBJECTIVE: To study the immunogenicity and safety of recombinant yeast-derived hepatitis B vaccine (YDV) on adults. METHODS: One hundred twenty-four healthy teachers of 22 - 58 years old, were randomly selected in Beipiao city, Liaoning province. Their HBsAg, anti-HBs and anti-HBc were all negative and temperature was normal. They were vaccinated with 5 microgram/0.5 ml of YDV, which was made in Beijing Institute of Biologic Products, at 0, 1, 6 months. RESULTS: The positive rates of anti-HBs were 35.0%, 83.3%, 67.2% (P < 0.01) with the mean geometric titre (GMT) of anti-HBs 12.63 mIU/ml, 402.04 mIU/ml and 70.28 mIU/ml (P < 0.01) at 3th, 7th, 12th months respectively. The positive rates of anti-HBs and GMT of anti-HBs became the highest at 7th month, then began to decrease sharply. At 3th, 7th, 12th months the positive rates of anti-HBs and GMT of anti-HBs were higher on female compared to male, but only GMT of anti-HBs was significantly different at 3th month; the positive rates of anti-HBs in below 35 years old group was higher than 35 and over years old group, but it was significantly different only at 12th month. GMT of anti-HBs between the two groups was no obvious difference. Local or systematic addictive reactions were not found in all the subjects in 3 days after injection. CONCLUSION: YDV is effective and safety to adults. The duration of anti-HBs should be further observed.

Adult↗
PubMed2001

[Excimer laser in situ keratomileusis for severe ametropia after penetrating keratoplasty].

OBJECTIVE: To evaluate the effects of excimer laser in situ keratomileusis in correcting severe myopia and astigmatism after penetrating keratoplasty. METHODS: Excimer laser in situ keratomileusis was performed on ten eyes of ten patients to correct high ametropia in cases having previously undergone penetrating keratoplasty. RESULTS: After surgery, all grafts remained clear and no corneal graft rejection occurred during the follow-up period. The average spherical equivalent refraction decreased from minus sign11.85 D preoperatively to minus sign3.38 D postoperatively and the average cylinder from 6.75 D to 2.70 D. The highest cylinder correction achieved was 10.00 D. The mean uncorrected visual acuity improved from 0.1 to 0.8, the best one was 1.5, and the best corrected visual acuity (BCVA) improved from 0.8 to 1.1. In this group, BCVA was improved in all eyes. CONCLUSION: Excimer laser in situ keratomileusis is a safe and effective method to deal with the high ametropia after penetrating keratoplasty and shows its great prospect.

Adult↗
PubMed2001

[Effect of high-vaccum-manual-chop technique in phacoemulsification].

OBJECTIVE: To study the effect of high-vaccum-manual-chop technique to reduce complications related to phacoemulsification. METHODS: The correlation between the relative energy complex parameter (RECP) and the postoperative corneal edema rate (CER) in manual-chop and phaco-divide groups was statistically studied. RESULTS: The intraoperative mean relative ultrasound power and the mean time of ultrasound phacoemulsification were increased with the increase of the lens nucleus hardness. A significant difference existed between the mean time of the ultrasound phacoemulsification of the two groups (t = 3.1467, P < 0.01). The comparison between the mean relative ultrasound power of the two groups has no significant difference (t = 0.1874, P > 0.05). Positive correlation was observed between RECP and CER (r = 0.97, P < 0.01). CONCLUSION: High-vaccum-manual-chop technique may reduce the postoperative complications related to phacoemulsification, and RECP can be taken as a reliable index to evaluate the safety of phacoemulsification.

Adult↗
PubMed2001

[The scleral buckling combined with argon laser photocoagulation for retinal detachment].

OBJECTIVE: To investigate the effects and indications of postoperative photocoagulation with argon laser instead of intraoperative cryotherapy for closing the retinal breaks during the scleral buckling operation in rhegmatogenous retinal detachment (RD) METHODS: An analysis of clinical data in 35 RD cases (38 eyes) was conducted retrospectively. These cases were treated by argon laser photocoagulation after the scleral buckling surgery from December, 1999 to April, 2000 in our hospital. RESULTS: Thirty-eight eyes were followed-up from 3 to 6 months. In 36 of 38 eyes, the retina was reattached after surgery (94.7%). Postoperatively, thirty-one eyes (86. 1%) had a visual acuity (VA) of >or= 0.05 and the best VA was 1.0. CONCLUSIONS: The method using postoperative photocoagulation instead of cryotherapy during scleral buckling surgery can simplify the surgical manipulations, alleviate the vessel damage of the retina and uvea and reduce the postoperative complications. It is a practicable way to treat RD. Surely, photocoagulation can not totally replace cryotherapy. Proper selection of indications and avoidance of complications of photocoagulation can elevate the successful rate of reattachment of RD, and promote the recovery of visual function.

Adolescent↗
PubMed2001

[E-cadherin associated protein expression and its significance in invasive lobular carcinoma and invasive ductal carcinoma of breast].

OBJECTIVE: To study E-cadherin associated proteins alpha-, beta-, gamma-catenin expression and their significance in invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) of breast. METHODS: Immunohistochemistry staining (labeled streptavidin-biotin method) was used to detect alpha-, beta-, gamma-catenin expression in invasive breast carcinoma (19 cases of ILC and 32 cases of IDC ). RESULTS: The loss and reduction rate of alpha-, beta-, gamma-catenin expression in ILC was 78.9% (15 cases), 52.6% (10 cases) and 84.2% (16 cases), respectively. The rate of alpha-, beta-, gamma-catenin expression showing loss and reduction in IDC was 75.0% (24 cases), 43.8% (14 cases) and 81.3% (26 cases), respectively. The staining intensity of alpha-, beta-, gamma-catenin expression in invasive carcinoma of breast was weaker than that in foci of carcinoma in situ (semiquantitative grading). There was a positive relationship between the expression of alpha-catenin and beta-catenin in invasive breast carcinoma. No significant association was seen between reduced protein expression of alpha-, beta-, gamma-catenin and the development of lymph node metastasis. CONCLUSION: alpha-, beta-, gamma-catenin expression was almost identical in ILC and IDC of breast, showing significant loss and reduction of protein expression in the carcinoma cells of invasive breast carcinoma, suggesting that alpha-, beta-, gamma-catenin may lose their normal adherent ability in the pathogenesis of invasive breast carcinoma.

Adult↗
PubMed2001

[A comparative study on wound healing treated by different doses of bovine basic fibroblast growth factor (bFGF)].

OBJECTIVE: To explore the optimal dosage and method of bFGF application on surgical wound for accelerating its healing. METHODS: Laceration wounds on the extremities of 73 patients were served as the target. The wounds were applied with three different doses of bFGF (75 Au/cm(2), 150 Au/cm(2), 300 Au/cm(2)) and with three application methods, i.e. once a day, three times a day and once a day with moistening. Normal saline with 0.5% metronidazol was employed as control agents. The wound healing time in every groups was recorded in days and compared with each other. RESULTS: When compared to each other, the wound healing time (day) was much shorter (P < 0.05) with bFGF application in dose of 75 similar 300 Au/cm(2). There were also obvious differences in wound healing time among groups treated with the same dose but with different methods (P < 0.01). In addition, three times a day and once a day with moistening of bFGF application could further shorten the wound healing time. CONCLUSION: Compared to the dosage of the agent, the frequency and method of bFGF application seemed more important for its optimal effects. In view of the convenience, feasibility and economy, once a day with moistening was recommended for clinical application.

Adolescent↗
PubMed2001

[An experimental study on the apoptosis of PMNs and macrophages during the early postburn stage in severely scalded rats].

OBJECTIVE: To investigate the changes of postburn apoptosis of PMN and the apoptosis of PMN and macrophages after being stimulated by burn sera and the change of the phagocytosis of apoptotic PMNs by macrophages. METHODS: Rats inflicted by 30% TBSA III degree scalding were employed as the model. PMNs were harvested on the 0, 6, 12 and 24 postburn hour (PBH). Burn sera were harvested at 24 PBHs. PMN apoptosis was detected by flow cytometry. Simultaneously, peritoneal macrophages were collected for the study. The apoptotic change of the macrophages (Mphis) after being stimulated by burn sera and the ability of Mphis phagocytizing apoptotic PMNs at 24 PBHs were examined. RESULTS: The PMN apoptosis was obviously inhibited at 6, 12 and 24 PBHs in the scalded rats with no difference between the time spots. Twenty-four hours after being stimulated by burn sera, the apoptotic rate of PMNs on scalded rats was lower than that in normal rats, while the apoptotic rate of Mphis in scalded rats was higher than that in normal rats. The ability of Mphis phagocytizing apoptotic PMNs decreased after severe burn (P < 0.01). CONCLUSION: There exhibited delayed rat PMN apoptosis and decreased ability of the phagocytosis of apoptotic PMNs by the Mphis after severe burn or being stimulated by burn sera. This might lead to the incomplete phagocytosis of apoptotic PMNs by Mphis. As a result, the PMNs would finally come to necrosis and release toxic contents which were important factors in the inducing of SIRS.

Animals↗
PubMed2001

[Carrier detection and prenatal diagnosis for hemophilia A].

OBJECTIVE: To establish a simple, rapid carrier detection and prenatal diagnosis system for hemophilia A. METHODS: Intron 22 inversion in FVIII gene was directly examined by long distance polymerase chain reaction. Polymorphism of factor VIII intragenic RFLP of Bcl I, STR within intron 13 and 22, and extragenic DXS 52 (St 14) VNTR loci by hereditary linkage analysis were assayed. RESULTS: The diagnostic rates of these loci were 47.6% (intron 22 inversion), 27.8% (Bcl I), 28.6% and 29.4% (STR within intron 13 and 22), and 81.3% (DXS52), respectively. The overall diagnostic rate in 21 families was 94.7%. CONCLUSIONS: The diagnosis in hemophilia A patients or carriers can be made if intron 22 inversion is present. The intragenic and extragenic loci hereditary linkage analysis could be used to establish the diagnosis in intron 22 inversion negative patients.

Factor VIII↗
PubMed2001

[Changes in the activity of platelet L-arginine/nitric oxide pathway in hypercholesterolemia patients].

OBJECTIVE: To investigate the changes of the platelet L-arginine (L-Arg)/nitric oxide (NO) pathway in hypercholesterolemia patients. METHODS: The platelet NO production in 21 hypercholesterolemia (HC) patients and 26 normal individuals was assayed by spectrum, the NOS activity and the transportation of L-Arg were determined by (3)H-labelled L-Arg. RESULTS: The NO production in hypercholesterolemic platelets [(24.06 +/- 3.70) nmol/10(8) platelets] was decreased significantly as compared with normal controls [(28.39 +/- 4.45) nmol/10(8) platelets] (P < 0.01), and so did the NOS activity [(1.46 +/- 0.47) pmol/10(8) platelets] vs (1.81 +/- 0.50) pmol/10(8) platelets]. The transportation of L-Arg by hypercholesterolemia platelets also decreased significantly than that by normal controls. The Vmax in the former [(46.84 +/- 3.39) pmol x (10(7) platelets)(-1) x min(-1)] was significantly lower than that in the latter [(53.89 +/- 3.45) pmol x (10(7) platelets)(-1) x min(-1)]. There was no difference between the two groups in K(d) (P > 0.05). CONCLUSIONS: The activity of the L-arg/NO pathway in hypercholesterolemia platelets is decreased significantly as compared with normal controls, implying that it is probably one of the reasons for the hyperactivity of hypercholesterolemia platelets.

Adult↗