Biomedical subjects

D Li

Publications and source records attributed to D Li.

At least 217 records · Page 12Linked to original sources

PubMed2001

[Water quality of closed polyculture of penaeid shrimp with tilapia and constricted tagelus].

A variety of water quality parameters were monitored in enclosures for the polyculture of penaeid shrimp with tilapia and constricted tagelus. The result showed that the environment of the polyculture systems was better than that of monoculture one. The fluctuation of DO in the water of polyculture enclosures was less violent, and their lowest values were obviously higher than those in monoculture ones. The value of COD and the number of bacteria in the water of polyculture enclosures were significantly lower than those in monoculture ones(t-test, alpha < 0.05), showing that the amount of organic matter in the water of polyculture systems was less than that in monoculture one. The biomass of plankton and the concentration of chlorophyll-a in the polyculture enclosures were also lower, showing that the suppression of the filtering animals to the plankton was obvious. The accumulation of N and P in the sediment of polyculture enclosures was 39.76% and 51.26%, lower than those of monoculture ones, respectively; and the number of bacteria in the sediment was 7.63% lower. Therefore, it is obvious that closed culture system can greatly decrease the effluent to the coastal waters caused by the pond culture industry, and decrease the pollution to the coastal waters.

Animals↗

PubMed2001

[Effect of silver carp stocking and fertilization on plankton community in enclosures in saline-alkaline ponds].

The effect of silver carp (Hypophthalmichthys molitrix) stocking and fertilization on plankton community of enclosures ecosystem in saline-alkaline ponds were studied. After stocking silver carp in enclosures, the abundance, chlorophyll-a content and primary productivity of phytoplankton increased, and the biomass of phytoplankton was mainly composed by small species, such as diatom and green algae. Moreover, Euglnophyta and Chrysophyta were also subdominant species. The biomass of zooplankton decreased with fish stocking, and that of Cladocera was greater in control than in fish-culture enclosures. Zooplankton community was dominated by larger species such as Daphnia carinata in control enclosures. Fertilization, especially applying inorganic fertilizer, significantly increased the abundance and primary productivity of phytoplankton and the biomass of zooplankton. Although the biomass of plankton in the enclosures applied organic fertilizer was greater than that of control enclosures, the primary productivity and chlorophyll-a content of phytoplankton, the diversity index of plankton, and the P/R ratio were very low, and thus, silver carp grew slowly. The effect of filter feeding fish and applying fertilizer on the structure of plankton community was also discussed.

Animals↗

PubMed2001

[Autotrophic ammonium-removal of sludge liquor].

The autotrophic ammonium-removal process was realized in floating bed reactors with sludge liquor as substrate. Biofilm of autotrophic bacteria were formed on the surface of carriers in reactors. The main operation conditions of the reactors were as the following: T = 28 degrees C, pH = 8.0 and DO = 0.8-1.0 mg/L. The average surface load of two reactors in series was NH4(+)-N 3-4 g/(m2.d), and the general autotrophic ammonium-removal efficiency was about 70%. The Autotrophic ammonium-removal technology promises considerable savings in regard to the oxygen consumption and external organic carbon addition compared with the conventional nitrification-denitrification technology when it was used to treat ammonium-rich and unfavourable C/N ratio wastewater.

Biofilms↗

PubMed2001

[A simple and rapid procedure for detection of DNA damage caused by Aldicarb].

A simple and rapid procedure for detection of low levels DNA damage caused by Aldicarb was developed and compared with some other methods. In the original position the gel was set in high-pH buffer to run electrophoresis after the diluent of bacteria or fragmentized organ was added into hole of agarose gel directly and cells were treated with detergent and high alkaline condition. The impact of Aldicarb to biological individual or ecosystem was assessed according to the quantity of DNA and the extent of DNA migration.

Aldicarb↗

PubMed2001

[The mandibular molar-area implantation of screw-typed dental implants].

OBJECTIVE: To study molar area implantation with screw-typed implant based on the specific anatomic properties of inferior alveolar nerve. METHODS: Depending on the degree of alveolar atrophy in mandibular molar area, the direct implantation, the buccal-to mandibular-canal implantation, and the repositioning inferior-alveolar-nerve implantation were employed. During the period of 1992 to 1998, a total of 22 cases of this kind with 45 dental implants were restored. The follow-up period was 5 years. RESULTS: 2 dental implants were lost respectively after 3 months of insertion and after 1 year of restoration. All the 43 others, however, still remained complete osseointegration, with no obvious crestal bone rebesorption and with excellent function. The 5-year accumulating survival rate of dental implants was 96%. CONCLUSIONS: These three surgical techniques, to a large extent, can solve the problems of mandibular molar area implantation. The key to success of each technique is the selection of patient and the selection of surgical project.

Adult↗

PubMed2001

[Role of costimulating molecule CD86 in maternal-fetal immune regulation].

OBJECTIVE: To evaluate the role of costimulating molecule CD86 in maternal-fetal immune regulation. METHODS: In abortion-prone (CBA x DBA/2) matings and non-abortion-prone (CBA x BALB/c) matings, the pregnant CBA females were injected intraperitoneally by purified rat anti-murine CD86 monoclonal antibody (mAb) with dosage of 100 micrograms at day 4, 6, 8 and 10 of gestation respectively, or injected only once at day 4 of gestation, or injected with purified rat IgG as control. The resorbing and non-resorbing embryos were enumerated at day 14 of gestation. RESULTS: The embryo resorbing rate in CBA x DBA/2 matings was 27.78%, and that in CBA x BALB/c matings was 8.42%. After injection of anti-CD86 mAb at day 4, 6, 8, 10 of gestation, the embryo resorbing rate reduced to 9.68% (P < 0.005) in CBA x DBA/2 matings, while that was 13.54% in CBA x BALB/c matings (P > 0.05). After injection of anti-CD86 mAb only once at day 4 of gestation, the embryo resorbing rate reduced apparently to 7.14% (P < 0.001) in CBA x DBA/2 matings, while that was 11.39% (P > 0.05) in CBA x BALB/c matings. CONCLUSIONS: Blocking the costimulating signal by anti-CD86 mAb at maternal-fetal interface, especially at the prime stage of maternal-fetal recognition (periods of implantation), may result in maternal-fetal tolerance, and hopefully the embryo resorption turns to normal pregnancy.

Animals↗

PubMed2001

The expression of AT1 receptor on hepatic stellate cells in rat fibrosis induced by CCl4.

OBJECTIVES: To assess the effect of an ACE inhibitor and an Ang II type 1 (AT1) receptor antagonist on preventing hepatic fibrosis induced by CCl4 in rats and to investigate whether there is the expression of AT1 receptors on hepatic stellate cells. METHODS: Studies were conducted in male Sprague-Dawley rats. Except for model group and control group, in three treated groups, either enalapril (5 mg/kg), or losartan (10 mg/kg), or enalapril + losartan were given to the fibrotic rats (daily gavage). Saline vehicle was given to the control group. After 6 weeks, liver fibrosis was assessed directly by hepatic morphometric analysis. The expression of AT1 receptors and alpha-smooth muscle actin (alpha-SMA) in liver tissue and isolated hepatic stellate cells (HSC) were detected by immunohistochemical techniques. RESULTS: Compared with the fibrosis in rats of the model group, rats treated with either enalapril or losartan, or a combination of two drugs, showed a limited expansion of the interstitium (P < 0.05), but no significant difference was observed among the three treated groups (P > 0.05). The expression of AT1 receptors was found in abundance in the fibrotic interstitium of the fibrotic rats, whereas in the normal control rats they were limited to the vascular wall. AT1 receptors were also expressed on activated HSC in culture plates. CONCLUSIONS: Angiotensin-converting enzyme inhibitors and AT1 blockers might slow the progression of hepatic fibrosis. Activated HSCs expressed AT1 receptors. Activation of RAS might be related to hepatic fibrogenesis induced by CCl4.

Alanine Transaminase↗

PubMed2001

[Apoptotic cells and related factors in ovariectomized rat osteoporosis model].

OBJECTIVE: To investigate the status of apoptosis of osteoblast, osteoclast and the relative factors. METHODS: Apoptotic cells were examined using in situ end labeling technique. Expressions of bcl-2, Fas and transforming growth factor(TGF) beta1 were observed with immunohistochemical method. RESULTS: Positive expression rate (40.5 +/- 5.2)% of apoptosis cells was significantly increased in the osteoblast, but the expression rate of apoptosis cells (8.4 +/- 1.2)% was significantly decreased in the osteoclast of the post-ovariectomy rats than in the sham-operated rats. The expression of Fas was decreased in osteoclast (20.0%) and increased in osteoblast (80.0%) of the post-ovariectomized rats. The expression of TGFbeta1 was significantly decreased in the osteoclast (0) and the osteoblast (20.0%) of the post-ovariectomized rats. The above-mentioned targets in post-ovariectomized rats treated with nylestriol/levonorgestrel were close to those sham-operated rats (P > 0.05). CONCLUSIONS: Bone loss in the post-ovariectomized rats is attributable to the lower level of estrogen so that the apoptosis cells were decreased in osteoclast but were increased in osteoblast. As a result, the process of bone absorption prevails over that of bone formation. Expression of TGFbeta1 depends on stimulation of estrogen. TGFbeta1 may stimulate apoptosis of osteoclast and restrain apoptosis of osteoblast. Fas can induce the apoptosis of osteoclast.

Animals↗

PubMed2001

[Treatment of malignant pleural effusion using vindesine and cisplatine intrapleurally injection (observation of 60 cases)].

OBJECTIVE: To evaluate the efficacy of treating malignant pleural effusion with cisplatine and vindesine by injection through thoracic tube intubation. METHODS: 60 cases with malignant pleural effusion, after drainage, vindesine 4 mg, cisplatine 40 mg/m(2) were injectred into pleural cavity in therapy group (T), and only cisplatine 40 mg/m(2) in control group (C). the tretment was repeated after a week, then evaluate the efficacy, survival rate, toxicities and quality of life. RESULTS: The response rate was 81% in T group and 50% in C group. There was statistical difference in two groups (P < 0.05). The Karnofsky score is higher in T group than in C group. The half-year, one-year, one and half-year, two-year survival rates were 97%, 59%, 44%, 6% in T group and 71%, 50%, 14%, 4% in C group. Grade I leukopenia is higher in T group than in C group. CONCLUSION: The treatment to use Vindesine and cisplatine through thoracic tube is regarded as effective, slight side-effect and well tolerated method for malignant pleural effusion.

Adolescent↗

PubMed2001

[Septorhinoplasty for nasal deviation complicated with septal cartilage deformity].

OBJECTIVE: To investigate a method for safe, simple and effective correction of nasal deviation complicated with the deformity of nasal septal cartilage. METHODS: From one side of the septal cartilage, the whole muco-perichondrium was separated, and from the other side a U-shaped muco-perichondrium was separated. The bottom of the septal cartilage was freed while a part of cartilage connected with the vomer was reserved. RESULTS: 12 patients were operated on with this technique for nasal deviation from March 1996 to August 1999. The follow-up period ranged from 1 to 12 months. The overall result was successful in all cases except one of recurrence. CONCLUSION: This technique not only provides wide space for removing the spetal cartilage, but also creates a cartilaginous framework to support the septal cartilage in the middle without lowing the nasal tip, which avoids the tendency of migrating to its original position caused by external fixation. This technique also ensures replacing the septal cartilage in the midline regardless of the deformity of anterior nasal spine and the vomer.

Adult↗

PubMed2001

[Vitreoretinal surgery with intraocular C3F8 tamponade for retinal detachment due to macular hole without face-down positioning].

OBJECTIVE: To evaluate the effectiveness of vitreoretinal surgery with 16% perfluoropropane (C3F8) tamponade without face-down positioning in treatment of retinal detachment due to macular hole. METHODS: Twenty-seven consecutive eyes in 27 patients with retinal detachment due to myopic macular hole underwent closed vitrectomy, membrane peeling, gas-fluid exchange with C3F8 tamponade in the whole vitreous chamber. In 3 eyes, phacoemulsification was performed, and 2 of them received intraocular lens implantation. Postoperatively, except avoiding the supine position, the body position was not restricted. RESULTS: Twenty-one cases (78%) obtained successful retinal reattachment without the postoperative face-down positioning. In another 6 cases, because of the relatively quick absorption of the gas, the white macular hole and the subretinal proliferation, the operation was not successful, the hole being not sealed and the retinal detachment at the lower part still existing. In the 3 cases with quick absorption of the gas, on the 10th day after the operation, the body position was changed into a face-down one. In 2 of them, the retinal reattachment occurred. After > 6 months of follow-up, the retinal reattachment remain the same in 22 cases (81%), the macular hole was healed, and the visual acuity was elevated to > or = 0.1 in 19 cases. The main complications were lens opacity in 6 cases (31%), temporary elevation of intraocular pressure in 3 cases (11%). CONCLUSION: Use the methods for the treatment of macular hole and retinal detachment mentioned above may obtain relatively good therapeutic results, particularly suitable for senile and unhealthy cases.

Aged↗

PubMed2001

[The survey of HIV prevalence among children between 0 to 7 years old in one county in China].

OBJECTIVE: To estimate the HIV prevalence among children between 0 to 7 years old in one county with HIV epidemic. METHODS: In September 2000, finger tip blood samples were collected from 619 children between 0 to 7 years old in three districts of one county with high HIV prevalence and tested for HIV antibody and HBV antigen. RESULTS: Among those 619 children, 11 were found HIV positive, with the prevalence of 1.8% (11/169). The HIV prevalence of three districts were 5.9% (10/169), 0.5% (1/206), and 0% (0/244), respectively. The possible channel associated with the HIV infection was mother-to-child transmission since none of the infected children had the history of blood transfusion. Twenty-four tested children were found HBV positive and the prevalence was 4.3 (24/619). CONCLUSION: There was higher HIV prevalence in children between 0 to 7 years old in certain areas. More intervenes are needed in the future to prevent the HIV spreading through mother-to-child transmission.

Child↗

PubMed2001

[Cloning and nucleotide sequencing of full length L segment cDNA of Hantavirus strain A9].

OBJECTIVE: Cloning and nucleotide sequencing of full length cDNA sequence of L segment of Hantavirus strain A9. METHODS: The L segment cDNA of Hantavirus strain A9 was amplified by RT-PCR. PCR products were cloned and sequenced. Full length cDNA clone of the L segment was obtained by subcloning. RESULTS: The L segment of strain A9 was 6 533 nucleotides in length and encoded a putative L polymerase that was 2 151 amino acids in length. Analysis of nucleotide and deduced amino acid sequences of the L segment of strain A9 showed a close relationship with the other Hantaviruses most notably the 76-118, Cl-1 and Cl-2 strains, with which they shared a 83.8% nucleotide identity. More distant similarity could also be seen with other Hantaviruses. Sequence comparison performed among the RNA-dependent RNA polymerases of 27 negative stranded RNA viruses revealed that the same existence of six conserved regions and several strictly conserved residues located at the deduced amino acid sequence of A9 L segment. CONCLUSIONS: The nucleotide sequence of L segment of strain A9 was similar to other Hantavirus L segments. Deduced amino acid sequence of A9 L segment shares 6 conserved regions with other RNA virus RNA polymerase. The conserved residues in these polymerases and their possible functions in light of the available structural information have been discussed.

Amino Acid Sequence↗

PubMed2001

[Establishment and characterization of three transplantable tumors of nasopharyngeal carcinoma in Scid mice].

BACKGROUND: To establish several transplantable tumors of nasopharyngeal carcinoma (NPC) in order to provide suitable models for study of EBV specific immunity and its application in treatment of NPC. METHODS: Balb/C nude mice and scid mice were used as transplantation host. Tumor tissues were obtained with forceps from nasopharyngeal tumors of twenty six untreated NPC patients and transplanted subcutaneously in axilla or back of mice with puncture trocar. Characteristics of the established transplantable tumors including the transplanting efficiency, growth rate, gross appearance morphology under optic microscope and electron microscope and karyotypes chromosome were investigated. Detection of LMP-1 as well as LMP-2 were performed for the transplantable tumors and cell lines with immunohistochemical methods. RESULTS: Three transplantable tumors were successfully established from 26 specimens of human nasopharyngeal carcinoma and mamed as CSNET-1, CSNET-2 and CSNET-3. The CSNET-1 was primarily generated in nude mice and then transplanted to scid mice after 3 passages. To date the CSNET-1, CSNET-2, CSNET-3 have been passed to 11th generation (23 months), 14th generation (17 months) and 9th generation (16 months), respectively. The overall success rates of transplantation were 91% (39/43), 97% (29/30) and 94% (34/36); The median time of latent growth were 23, 38 and 20 days;and longest persistence of tumor in vivo were 93, 38 and 44 days, respectively, for the above tumors. The karyotypes of all transplantable tumors displayed as typical human origin with hyperdiploid chromosomal and multiple structure aberration. Histologically, the tumors possess the characteristics of poor differentiated squamous carcinoma under either microscope or electron microscope. Some particles minimizing mature EBV were found in CSNET-1 under electron microscope. Either LMP-1 or LMP-2 were detectable in CSNET-1, CSNET-2, and CSNET-3 by immunohistochemical test. CONCLUSIONS: The transplantable tumors CSNET-1, CSNET-2 and CSNET-3 are of human origin and able to pass steadily in scid mice. They possess the characteristics of poorly differentiated squamous carcinoma similar to their prime tumors in human and express EBV LMP-1 and LMP-2. These tumors seemed to be suitable models in the study of immunotherapy for NPC.

Animals↗

PubMed2001

[A survey on the effects of "Dietary Guideline" nutrition education project].

A survey on the nutrition knowledge, attitude and behavior of 5145 persons from five cities of four provinces, Shandong, Guangdong, Sichuan and Heilongjiang, before and after the nutritional education project on "Dietary Guideline" has been effectively conducted. An obviously good effect has been achieved among the residents, middle and primary school students and elderly people. Before the nutritional educational project has been carried out, the people who understanding the "Dietary Guideline" was only 12.0%, 29.2% and 15.2% of residents, the elderly and students respectively. But after education, the rates raised to 93.4%, 99.0% and 91.9% respectively. Nearly 90% of residents and the elderly got to know the "Dietary Guideline" through the materials distributed from the project. The nutrition knowledge score was improved greatly after the project was conducted. The attitude towards learning nutrition knowledge was good. At the same time, some dietary behavior and the life style of people had been modified. These results indicated that nutrition education is very important on improving people's nutrition knowledge level, changing people's unhealthy living attitudes and dietary habits.

Adolescent↗

PubMed2001

[Detection and partial nucleotide sequence analysis of hepatitis G virus in sera of patients with hepatitis in Guangzhou].

OBJECTIVE: To investigate hepatitis G virus (HGV) infection in hepatitis patients and the gene type of HGV in Guangzhou. METHODS: Reverse transcriptase-nested polymerase chain reaction(RT-nested PCR) method using primers locating in noncoding region of HGV genome was used for detecting HGV RNA in sera of hepatitis patients and the amplified products were directly sequenced. RESULTS: 25 cases were HGV RNA positive in 251 sera of acute and chronic hepatitis(9.96%), of which 4 cases were positive in 56 sera with hepatitis non A-E(7.14%), 8 cases were positive in 77 sera with hepatitis B (10.39%), 13 cases were positive in 118 sera with hepatitis C(11.17%). The identity of nucleotide sequence was 98.0% between 2 Guangzhou HGV isolates, both were 91.1% with American isolate, 81.7% and 84.2% respectively between 2 Guangzhou isolates and African isolate. CONCLUSION: HGV infection exists in hepatitis patients, 2 Guangzhou HGV isolates may belong to the same gene type and both of them have a high homology with American HGV isolate.

Base Sequence↗

PubMed2001

[Detection of S-100 protein in laryngeal carcinoma].

OBJECTIVE: To study the relationship between S-100 protein and prognosis of laryngeal carcinoma. METHOD: S-100 protein was observed by immunohistochemical methods using anti-S-100 protein antibody in 68 laryngeal carcinoma and 21 non-cancer laryngeal tissues. RESULT: The result showed that S-100 protein positive were found 43 (63.24%) in 68 laryngeal carcinoma. S-100 protein positive cells were interspersed among the tumor cells and in the stroma. S-100 protein were rare in non-cancer laryngeal tissues. The five-year survival rate in patients with S-100 protein positive was significantly higher than that in patients with S-100 protein negative. CONCLUSION: Our result indicated that the detection of S-100 protein is of value for the prognostic analysis in patients with laryngeal carcinoma.

Humans↗

PubMed2001

[Cloning of promelittin cDNA and its expression in Escherichia coli].

The cDNA encoding promelittin was obtained from the total RNA of bee poison gland by RT-PCR and was cloned to pT7Blu-T vector. The expression vector of promelittin fused with partial sequence of beta-galactosidase was constructed by ligating the fragment inserted to pUC118. Moreover, it was expressed in the strain DH5 alpha of Escherichia coli. The result of DNA sequence analysis demonstrated that the obtained cDNA sequence was same with the published one and the reading frame of fusion gene was correct.

Animals↗