Biomedical subjects

L Fu

Publications and source records attributed to L Fu.

At least 55 records · Page 3Linked to original sources

PubMed2001

Study on detecting antibodies to Toxoplasma gondii in pooled serum of blood donors by Dot-IGSS.

To prevent post-transfusion toxoplasmosis, the sera of blood donors, per six of which were mixed as a pool, were examined for anti-Toxoplasma gondii antibiodies by Dot-immunogold silver staining (Dot-IGSS) with the single serum specimens examined simultaneously. The results showed that the sensitivity and specificity of serum pool method were 92.31% and 99.96% respectively. The consistent rate between the two methods was 99.73% and kappa value was 0.947 (p<0.01). Considering the mean infection rate of Toxoplasma gondii being 4.86% in China, if the serum pool method be adoped, with pool size k=5, a 57% reduction in the number of tests, as well as the cost of the screen, can be expected. Beside the social benefit, consequent upon the interruption of the Toxoplasma gondii infection spread through blood transfusion also can be expected.

Animals↗

PubMed2001

[Comparative analysis on the hearing ability of children in iodine deficiency areas born before and after iodine supplementation].

UNLABELLED: According to the detection of hearings ability of children in iodine deficiency areas who was born before and after iodine supplement, the effects of iodine supplement on hearing system development was evaluated. METHOD: Hearing was tested by AS-72 type pure zone diagnostic audiometer(made in Denmark). Hearing of 11-14 years old students were tested before iodine supplement in iodine deficiency areas in 1984, the control was students living in non-iodine deficiency areas. Iodine salt (50 mg/kg) were supplied by the end of 1984, the hearings of children born after one year of iodine supplied were tested in 1999. The result showed that the average hearing threshold of students before iodine supplied in iodine deficiency areas was significance higher than of non-iodine deficiency areas. The hearing of children born after one year of iodine salt supplied in deficient areas had no significant difference from that of normal areas. The development of hearing system might be deteriorated by iodine deficiency during pregnant. It was able to meet the need of iodine that pregnant women ate 1:20 thousands iodine salt.

Child↗

PubMed2001

[Pharmacokinetic studies of 20(R)-ginsenoside RG3 in human volunteers].

AIM: To study the pharmacokinetics of 20 (R)-ginsenoside Rg3 (GRg3) in human. METHODS: High-performance liquid chromatography-ultraviolet detection method was used in this study. RESULTS: The pharmacokinetics of GRg3 in 14 healthy volunteers were investigated. After a single oral dose of 3.2 mg.kg-1 in 8 male volunteers, the plasma concentration-time course fitted well to a two-compartment open model, with the following pharmacokinetic parameters: Tmax(0.66 +/- 0.10) h, Cmax(16 +/- 6) ng.mL-1, T1/2 alpha(0.46 +/- 0.12) h, T1/2 beta(4.9 +/- 1.1) h, T1/2(Ka)(0.28 +/- 0.04) h, AUC0-infinity(77 +/- 26) ng.mL-1.h. No kinetic analysis was made after an oral dose of 0.8 mg.kg-1 GRg3 in 6 other volunteers because of the low concentration, but a good correlation between Cmax and dosage of the two groups was found. CONCLUSION: The absorption of GRg3 was rapid in man, and its elimination was rapid after oral administration of ginsenoside Rg3. The pharmacokinetic results shows that it exhibited first order kinetic characteristics.

Adult↗

PubMed2001

[Removal of large acoustic neuroma via suboccipito-retrosigmoid approach with microsurgical technique].

OBJECTIVE: To probe the treatment effects of large acoustic neuroma (LAN) via a suboccipito-retrosigmoid microsurgical operation. METHODS: 216 patients with LAN in the cerebellar pons angle were confirmed by CT or MRI in our department. Each tumor (diameter > or = 31 mm) was removed via a suboccipito-retrosigmoid microsurgical approach. Treatment results were evaluated and the preoperative and postoperative function of the acoustic nerve or the facial nerve was compared separately. RESULTS: The tumors were totally removed in 172 patients(79.6%), subtotally removed in 33 (15.3%), and partially removed in 11 (5.1%). Anatomic preservation of the acoustic nerve was achieved in 27 patients (12.5%), and functional preservation in 9 patients (Grade A, 4.2%) at discharge. Anatomic preservation of the facial nerve was achieved in 178 patients (82.4%) and functional preservation in 94 (House Grade, Grade I - II, 52.8%) at discharge. Follow-up observation (Median: 3.9 years) of 187 patients revealed good recovery in 128 patients (68.4%), fair recovery in 44 (23.5%), and poor recovery in 15 (8.0%). Late recurrence was noted in those with poor recovery (10 patients, 5.4%) (cured by second treatment). CONCLUSIONS: It is a safe and effective way to remove LAN via suboccipito-retrosigmoid approach with microsurgical technique.

Adult↗

PubMed2000

Loss of the major isoform of phosphoglucomutase results in altered calcium homeostasis in Saccharomyces cerevisiae.

Phosphoglucomutase (PGM) is a key enzyme in glucose metabolism, where it catalyzes the interconversion of glucose 1-phosphate (Glc-1-P) and glucose 6-phosphate (Glc-6-P). In this study, we make the novel observation that PGM is also involved in the regulation of cellular Ca(2+) homeostasis in Saccharomyces cerevisiae. When a strain lacking the major isoform of PGM (pgm2Delta) was grown on media containing galactose as sole carbon source, its rate of Ca(2+) uptake was 5-fold higher than an isogenic wild-type strain. This increased rate of Ca(2+) uptake resulted in a 9-fold increase in the steady-state total cellular Ca(2+) level. The fraction of cellular Ca(2+) located in the exchangeable pool in the pgm2Delta strain was found to be as large as the exchangeable fraction observed in wild-type cells, suggesting that the depletion of Golgi Ca(2+) stores is not responsible for the increased rate of Ca(2+) uptake. We also found that growth of the pgm2Delta strain on galactose media is inhibited by 10 microM cyclosporin A, suggesting that activation of the calmodulin/calcineurin signaling pathway is required to activate the Ca(2+) transporters that sequester the increased cytosolic Ca(2+) load caused by this high rate of Ca(2+) uptake. We propose that these Ca(2+)-related alterations are attributable to a reduced metabolic flux between Glc-1-P and Glc-6-P due to a limitation of PGM enzymatic activity in the pgm2Delta strain. Consistent with this hypothesis, we found that this "metabolic bottleneck" resulted in an 8-fold increase in the Glc-1-P level compared with the wild-type strain, while the Glc-6-P and ATP levels were normal. These results suggest that Glc-1-P (or a related metabolite) may participate in the control of Ca(2+) uptake from the environment.

Calcium↗

PubMed2000

Human BAC ends quality assessment and sequence analyses.

End sequences from bacterial artificial chromosomes (BACs) provide highly specific sequence markers in large-scale sequencing projects. To date, we have generated >300,000 end sequences from >186,000 human BAC clones with an average read length of >460 bp for a total of 141 Mb covering approximately 4.7% of the genome. Over 60% of the clones have BAC end sequences (BESs) from both ends representing more than fivefold coverage of the human genome by the paired-end clones. Our quality assessments and sequence analyses indicate that BESs from human BAC libraries developed at The California Institute of Technology (CalTech) and Roswell Park Cancer Institute have similar properties. The analyses have highlighted differences in insert size for different segments of the CalTech library. Problems with the fidelity of tracking of sequence data back to physical clones have been observed in some subsets of the overall BES dataset. The annotation results of BESs for the contents of available genomic sequences, sequence tagged sites, expressed sequence tags, protein encoding regions, and repeats indicate that this resource will be valuable in many areas of genome research.

Chromosome Mapping↗

PubMed2000

Stable and full rescue of the pigmentation in a medaka albino mutant by transfer of a 17 kb genomic clone containing the medaka tyrosinase gene.

In the medaka Oryzias latipes, several albino strains have mutations in the tyrosinase gene that have been fully characterized at the molecular level. A genomic clone from wild-type medaka containing the 5 kb tyrosinase gene with its five exons, 10 kb of upstream sequences and 2 kb downstream sequences was introduced into fertilized eggs from a tyrosinase-negative albino strain. We show that the injection of this genomic clone predominantly conferred mosaic expression ending before the hatching stage. A minority of juveniles retained a variable number of pigmented cells, including four individuals keeping one pigmented eye through adulthood. Two of these could be mated, and one of these transmitted the transgene resulting in complete rescue of pigmentation to 16% of its offspring. The resulting transgenic line harbors a single copy of the wild-type tyrosinase gene and all fish are wild-type with respect to pigmentation. These experiments suggest that the tyrosinase genomic clone, or a future shorter version of it, can be used in fish to routinely detect transgenic lines. The apparent faithful and systematic expression of the tyrosinase transgene is most probably due to the presence of a locus control region (LCR) in the injected clone.

Albinism↗

PubMed2000

Clinicopathological characteristics of atypical cystic duct (ACD) of the breast: assessment of ACD as a precancerous lesion.

To clarify the clinicopathological features of an atypical cystic duct (ACD) as defined by Tsuchiya's criteria as a precancerous lesion of the breast, we used 200 whole mammary gland serial sections of breast cancer. Forty-four (22%) of the 200 breast cancer patients had ACD breast lesions. The frequency of patients with ACD increased in premenopausal women (P = 0.001). There was no correlation between the ACD-present group and the ACD-absent group for immunohistochemical status of the estrogen receptor (ER), progesterone receptor (PgR), p53, or c-erbB2; Ki-67 labeling index of cancer tissues; size of tumor, or lymph node metastases. A number of ACD lesions displayed continuity to cancer lesions. In 500 serial sections of a paraffin-embedded tissue of a ACD case at 3 microm intervals, an apparent transition from ACD into ductal carcinoma in situ was observed. Immunohistochemical analysis using alpha-smooth muscle actin showed that myoepithelial cells of ACD stained strongly, and their nuclei and cytoplasm were thinning. In 16 of the 44 (36%) ACD-present patients, carcinoma cells stained positive for p53. Within those 16 cases, 12 cases (75%) were positive for p53 in ACD lesions. There was a significant correlation between the expression of p53 protein in malignant cells and ACD (P = 0.001). All 44 ACD lesions had no staining of c-erbB2, regardless of staining in malignant lesions. The mean Ki-67 labeling index of ACD lesions was low (0.3%), suggesting that ACD had a low proliferative rate. We suggest that ACD is the precancerous breast lesion because of a histologic continuum between ACD and malignancy, and because of p53 protein expression in ACD.

Adult↗

PubMed2000

Molecular cloning and characterization of a new neuron-specific homologue of rat polypyrimidine tract binding protein.

Cancer-associated retinopathy (CAR) is a rare form of retinal degeneration and also one of the paraneoplastic neurologic disorders. Sera of CAR patients usually contain high titers of antibodies against retinal proteins, and CAR is believed to be an autoimmune disease. Using serum from a CAR patient as a molecular probe, a homologue of the polypyrimidine tract-binding protein (PTB) was isolated from a cDNA library of rat neonatal retina. This homologue, named PTB-like protein (PTBLP), encodes a 532 amino acid residue protein and has 73.5 and 68.8% homology with PTB and with a regulator of differentiation 1, respectively. Functional domains in the PTB, such as nuclear localization signals and four RNA recognition motifs (RRMs), were highly conserved. The expression of PTBLP mRNA was observed in the retina and brain but not in liver, kidney, spleen, or lung. The expression of PTBLP protein in rat retina was distributed in most of the cells in the ganglion cell layer and some cells in the inner nuclear layer. The PTBLP protein was localized in the nuclei of these cells. These results suggest that PTBLP is a new member of the PTB gene family and a neuron-specific homologue.

Amino Acid Sequence↗

PubMed2000

Characterization of novel human hepatoma cell lines with stable hepatitis B virus secretion for evaluating new compounds against lamivudine- and penciclovir-resistant virus.

L-Nucleoside analogs are new therapeutic agents for treatment of chronic hepatitis B. However, their clinical application was limited by the emergence of viral resistance. It is important to develop a new system to evaluate drug cross-resistance and to test new agents that may overcome resistant virus. In this report, three cell lines HepG2-WT10, HepG2-SM1, and HepG2-DM2 are presented; these cell lines were established by transfection of HepG2 cells with unique fully functional 1.1x hepatitis B virus (HBV) genomes: wild-type HBV-adr and its L526M and L526MM550V variants, respectively. We have demonstrated that these genomes have different susceptibilities to lamivudine [L(-)SddC] and penciclovir (PCV). By examining HBV RNA transcription, antigen expression, progeny DNA replication, and viral susceptibilities to L(-)SddC, PCV, and other nucleoside analogs, it is concluded that the cell lines are able to stably produce L(-)SddC- and PCV-sensitive and -resistant HBV virions. In addition, the relative susceptibilities of the wild-type and mutant HBV produced from the stably transfected cell lines to several anti-HBV nucleoside analogs were also examined and found to be about the same as those found by using a transient infection system. PMEA [9-(2-phosphonylmethoxytehyl)-adenine] and QYL685 are able to suppress L(-)SddC- and PCV-resistant HBV. In conclusion, this cell culture system is a novel and useful tool for evaluating anti-HBV compounds and biologics.

Acyclovir↗

PubMed2000

Demyelination determinants map to the spike glycoprotein gene of coronavirus mouse hepatitis virus.

Demyelination is the pathologic hallmark of the human immune-mediated neurologic disease multiple sclerosis, which may be triggered or exacerbated by viral infections. Several experimental animal models have been developed to study the mechanism of virus-induced demyelination, including coronavirus mouse hepatitis virus (MHV) infection in mice. The envelope spike (S) glycoprotein of MHV contains determinants of properties essential for virus-host interactions. However, the molecular determinants of MHV-induced demyelination are still unknown. To investigate the mechanism of MHV-induced demyelination, we examined whether the S gene of MHV contains determinants of demyelination and whether demyelination is linked to viral persistence. Using targeted RNA recombination, we replaced the S gene of a demyelinating virus (MHV-A59) with the S gene of a closely related, nondemyelinating virus (MHV-2). Recombinant viruses containing an S gene derived from MHV-2 in an MHV-A59 background (Penn98-1 and Penn98-2) exhibited a persistence-positive, demyelination-negative phenotype. Thus, determinants of demyelination map to the S gene of MHV. Furthermore, viral persistence is insufficient to induce demyelination, although it may be a prerequisite for the development of demyelination.

Animals↗

PubMed2000

Health risks of rural water supply due to lack of proper sanitation in southeast Asian countries.

A comparative study on the effects of lack of sanitation and inappropriate waste handling on water supply was carried out in several Southeast Asian countries that have problems such as inadequate water resources, water supply and sanitation. Though the degree and the cause varied in each country, all the countries investigated had problems arising from contamination of water resources. It was found that there are several sources of water contamination, such as human and animal excreta, solid wastes from nearby houses, graveyards, contaminated river flows, and large-scale landfills for big cities. It was revealed that even when water is clean at the point of production, it could be easily contaminated through broken pipelines or improperly maintained containers. It is still rare to put chlorine into piped water supply and both the inhabitants' and water engineers' understanding of the importance of disinfection should be reemphasised. Although it is urgent to provide piped water supply to those who have only contaminated water sources, such as surface water and dug wells, it is also important to protect these limited water sources from the above-mentioned contamination.

Asia, Southeastern↗

PubMed2000

In vitro evaluation of schedule-dependent interactions between docetaxel and doxorubicin against human breast and ovarian cancer cells.

Docetaxel, a novel member of the taxoid family, has shown greater potency than paclitaxel in the treatment of advanced breast cancer and certain other solid tumors. The promising clinical activity of docetaxel has also promoted considerable interest in combining this drug with other antitumor agents. In this study, we assessed the cytotoxic interaction between docetaxel and doxorubicin administered at various schedules to human breast and ovarian cancer cells. Through a series of in vitro assays including DNA fragmentation analyses, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, and flow cytometric analyses, we found that the antagonistic interaction occurred when tumor cells were exposed to the two drugs simultaneously or exposed to doxorubicin before docetaxel. However, no antagonism was observed when docetaxel was added before doxorubicin. Further analyses demonstrated that doxorubicin could interfere with the cytotoxic effect of docetaxel on both mitotic arrest and apoptotic cell death. In addition, biochemical examinations revealed that docetaxel could induce phosphorylation of both bcl-2 and c-raf-1, but these changes were inhibited when tumor cells were pretreated or simultaneously treated with doxorubicin. These results indicate that the interaction between docetaxel and doxorubicin is highly schedule dependent. Exposure of tumor cells to doxorubicin before docetaxel could result in pronounced antagonism. The optimal schedule for this combination might be sequential exposure to docetaxel followed by doxorubicin.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2000

Modeling traffic-related air pollution in street canyons of Beijing.

It is important to develop a general model to accurately simulate the air pollution in urban street areas. In this paper, the Operational Street Pollution Model (OSPM) initially developed in Denmark is tested with measured data from a relatively wide and open street in Beijing. Major factors influencing the dispersion, such as emission factors, stationary source emissions, and solar radiation, are analyzed. Results show that the model can reflect the basic dispersion pattern in the street but gives systematically higher concentrations. After modifications to estimate street-level wind speed in the model, performance is obviously improved.

Air Movements↗

PubMed2000

[An investigation of malocclusion deformity of 2002 middle school students in Fuchuan Yao race autonomous county of Guangxi Zhuang race autonomous region].

OBJECTIVE: To investigate the situation of maloccluson deformity which happens among the middle school students in Fuchuan Yao race autonomous county. METHODS: 2002 students (from 13 years old to 22 years old) were examined under natural light by using the way from Huang Jing fang, who edited a book called Oral Orthodontics. RESULTS: The rates of malocclusion deformity were 45.4% and 28.9% respectively, when the ideal normal occlusion and individual normal occlusion were treated as the criteria. CONCLUSION: Being compared with the relative reports, the results of the investigation show that the rate of malocclusion deformity is lower than that of the students in northern China.

Adolescent↗

PubMed2000

[A clinical study on PA-MSHA vaccine used for adjuvant therapy of lymphoma and lung cancer].

The objective of this study was to evaluate the effectiveness and safety of pseudomonas aeruginosa MSHA vaccine (PA-MSHA vaccine) used as an immune modulator. The study was carried out after the design of a non-blind, randomized controlled trial. The malignant lymphoma patients were divided into experiment group (45 cases) and control group (43 cases). Likewise were distributed the lung cancer patients: 44 cases in experiment group and 45 cases in control group. The two experiment groups received chemotherapy + PA-MSHA vaccine. The two control groups were given chemotherapy alone. The results showed that the clinical efficacy rate was 95.56% for the exp. group and 69.77% (P < 0.01) for the control group of the malignant lymphoma cases; the clinical efficacy rate was 59.09% for the exp. group and 42.22% (P < 0.01) for the control group of the lung cancer cases. The infection rate was 17.78% for the exp. group and 37.21% (P < 0.05) for the control group of the malignant lymphoma cases; the infection rate was 15.91% for the exp. group and 40.00% (P < 0.05) for the control group of the lung cancer cases. The comprehensive immune effectiveness rates for the exp. group and control group of the malignant lymphoma cases were 77.78% and 23.26% (P < 0.01) respectively. The comprehensive immune effectiveness rates for the exp. group and control group of the lung cancer cases were 84.09% and 35.56% (P < 0.01) respectively. Adverse reactions were found in 5 cases, of which, one was given medical care while the others automatically recovered. These results indicate that PA-MSHA vaccine, as a new kind of immune modulator, can improve the effectiveness of treatment for tumor with low adverse reaction rate.

Adjuvants, Immunologic↗

PubMed2000

[Cloning and sequence analysis of E0 gene of hog cholera virus lapinized Chinese strain and virulent shimen strain].

According to the published nucleotide sequences of genome of hog cholera virus, one pair of specific primers were designed and synthesized. From the spleen of rabbits which were infected with HCLV and HCV Shimen strain infected pig blood, the two E0 genes were amplified by RT-PCR. The amplified fragments were cloned into pGEM-T vector and sequenced. Sequence analysis showed nucleotide sequence and deduced amino acid sequence homologies of the E0 gene between HCLV and Shimen strain were 95.0% and 94.3%. There was 13 amino acid substitutions between them. One N-glycosylation site was missing from E0 gene of the Shimen strain. The nucleotide sequence homologies of the Shimen strain with the ALD, GPE-, Brescia and Alfort strains were 97.4%, 96.5%, 92.2% and 86.5%, respectively, the deduced amino acid sequence homologies were 97.4%, 96.0%, 95.2% and 92.5%, respectively. The nucleotide sequence homologies of E0 gene of the HCLV strain with the ALD, GPE-, Brescia and Alfort strains were 95.6%, 94.9%, 91.3% and 85.5%, respectively, the deduced amino acid sequence homologies were 93.4%, 92.5%, 91.6% and 90.7%, respectively. E0 gene from HCV was shown to be similar to a family of fungal and plant ribonuclease. The catalytically important residues were 28 to 40 and 71 to 89 of HCV E0 gene.

Amino Acid Sequence↗

PubMed1999

A translation repressor element resides in the 3' untranslated region of human p53 mRNA.

The 3' untranslated region of human p53 mRNA represses translation both in vitro and in vivo. Here, we identify a cis-acting 66-nucleotide U-rich sequence in the human p53 mRNA 3' untranslated region that mediates translational repression. Using UV cross-linking, we detect a 40 kDa protein that interacts specifically with the p53 3'UTR containing the repressor element. Enhanced translation of p53 mRNA contributes to the accumulation of p53 protein in cells exposed to gamma-radiation and could be a consequence of relieving the inhibition mediated by the repressor element.

3' Untranslated Regions↗