Biomedical subjects

Q Zeng

Publications and source records attributed to Q Zeng.

At least 19 recordsLinked to original sources

PubMed2001

Recombinant paramyosin (rec-Sj-97) tested for immunogenicity and vaccine efficacy against Schistosoma japonicum in mice and water buffaloes.

A primary vaccine candidate antigen against schistosomiasis is paramyosin (pmy), a myofibrillar protein found exclusively in invertebrates. Here we report the results of vaccine trials against the Asian schistosome undertaken on inbred and outbred mice and water buffaloes using a bacterially expressed and purified form of Schistosoma japonicum pmy (rec-Sj-97). Vaccination of the mice resulted in high levels of specific anti-pmy IgG antibodies when compared with adjuvant controls and significant reduction in worm burdens and in liver eggs. Furthermore, a significant reduction in liver eggs was recorded in two of the three water buffalo vaccine trials undertaken and, in all three trials, high levels of specific anti-pmy IgG antibodies were generated. There was no evidence of any toxic effects and the vaccine preparations and Quil A adjuvant were clearly well tolerated. The development of a vaccine intended for livestock animals such as bovines would be beneficial in two ways; directly by blocking transmission of schistosomiasis to humans and economically by contributing to healthier livestock. We are encouraged by the consistent efficacy in the mouse and the buffalo vaccine trials that resulted in a significant decrease in liver eggs. Indeed, predictions from mathematical models indicate that an egg reduction effect of 42-45% in buffaloes would be sufficient when combined with human treatment to control schistosomiasis japonica in the marshes and lakes along the middle and upper reaches of the Yangtze River, the most highly endemic areas for the disease in China.

Animals↗

PubMed2001

Abrogation of transforming growth factor-alpha/epidermal growth factor receptor autocrine signaling by an RXR-selective retinoid (LGD1069, Targretin) in head and neck cancer cell lines.

Clinical studies have demonstrated that retinoids, including retinol (Vitamin A) and its synthetic derivatives, can eradicate leukoplakia and suppress the formation of squamous cell carcinoma of the head and neck (SCCHN). Nonselective retinoids have been shown to abrogate transcriptional activation of transforming growth factor-alpha (TGF-alpha) and epidermal growth factor receptor (EGFR), which characterize SCCHN. LGD1069 (Targretin) is a potent RXR-selective retinoic acid agonist with a reduced toxicity profile compared with other nonselective retinoids. We examined the effect of LGD1069 (10 microm) on cellular proliferation and expression of putative intermediate biomarker genes including TGF-alpha, EGFR, and RAR-beta in seven SCCHN cell lines. A quantitative reverse transcription-PCR assay using a novel "primer dropping" method was used to determine expression levels of EGFR, TGF-alpha, and RAR-beta before and after treatment with LGD1069 (10 microM). SCCHN proliferation was reduced by a mean of 50% at 4 days in seven SCCHN cell lines after LGD1069 treatment (P < or = 0.05). EGFR expression levels were decreased by a mean of 58.4% (P = 0.007), TGF-alpha levels were decreased by a mean of 28.8% (P = 0.01), and RAR-beta levels were increased by a mean of 60% (P = 0.03). TGF-alpha stimulation of EGFR is associated with constitutive signal transducer and activator of transcription 3 (Stat3) activation in SCCHN. Abrogation of constitutive Stat3 activation was seen with LGD1069 treatment. These results suggest that an RXR-selective retinoic acid decreases SCCHN proliferation in part by interfering with TGF-alpha/EGFR autocrine signaling.

Animals↗

PubMed2001

Interaction of farnesylated PRL-2, a protein-tyrosine phosphatase, with the beta-subunit of geranylgeranyltransferase II.

Protein of regenerating liver (PRL)-1, -2, and -3 comprise a subgroup of closely related protein-tyrosine phosphatases featuring a C-terminal prenylation motif conforming to either the consensus sequence for farnesylation, CAAX, or geranylgeranylation, CCXX. Yeast two-hybrid screening for PRL-2-interacting proteins identified the beta-subunit of Rab geranylgeranyltransferase II (betaGGT II). The specific interaction of betaGGT II with PRL-2 but not with PRL-1 or -3 occurred in yeast and HeLa cells. Chimeric PRL-1/-2 molecules were tested for their interaction with betaGGT II, and revealed that the C-terminal region of PRL-2 is required for interaction, possibly the PRL variable region immediately preceeding the CAAX box. Additionally, PRL-2 prenylation is prequisite for betaGGT II binding. As prenylated PRL-2 is localized to the early endosome, we propose that this is where the interaction occurs. PRL-2 is not a substrate for betaGGT II, as isoprenoid analysis showed that PRL-2 was solely farnesylated in vivo. Co-expression of the alpha-subunit (alpha) of GGT II, betaGGT II, and PRL-2 resulted in alpha/betaGGT II heterodimer formation and prevented PRL-2 binding. Expression of PRL-2 alone inhibited the endogenous alpha/betaGGT II activity in HeLa cells. Together, these results indicate that the binding of alphaGGT II and PRL-2 to betaGGT II is mutually exclusive, and suggest that PRL-2 may function as a regulator of GGT II activity.

Amino Acid Sequence↗

PubMed2001

Functional polymer affinity matrix for purifying hexahistidine-tagged recombinant protein.

A functional polyacrylic acid (PAA) adsorbent has been prepared for metal chelate affinity chromatography. It has been found to chelate nickel ion Ni2+ strongly, and was evaluated for the ability to bind proteins containing neighbouring histidine residues. The principle of the technique was illustrated with Aeromonas hydrophila outer membrane protein OmpTS. DNA elements coding for adjacent histidines were fused to the Aeromonas hydrophila ompTS gene. Subsequent expression in E. coli resulted in the production of hybrid protein His6-OmpTS that could be purified by Ni2+-PAA affinity chromatography. The remarkable specificity found makes it an attractive addition to the range of adsorbents for metal chelate affinity chromatography.

Adsorption↗

PubMed2001

Comparison of heartworm antigen test kit performance in dogs having low heartworm burdens.

Sensitivity and specificity of four in-clinic heartworm antigen test kits, AbboScreen (Abbott Laboratories), Snap PF (IDEXX Laboratories), Solo Step (HESKA Corporation), Witness (Synbiotics Corporation) and two heartworm antigen microwell plate assays, DiroCHEK (Synbiotics) and PetChek PF (IDEXX) were compared in a blinded study using serum or plasma drawn from 237 random source dogs, including 140 with necropsy-confirmed, low worm burden infections (minimum 1 worm, maximum 10, mean 2.3, median 3) and 97 confirmed heartworm-free at necropsy. In general, microwell format tests were more sensitive than membrane format tests and tests using ELISA technology were more sensitive than tests using lateral flow immunochromatographic technology. Percent sensitivity and specificity, respectively, were PetChek PF 76 and 97, DiroCHEK 71 and 94, SNAP PF 67 and 98, Solo Step 60 and 98, and AbboScreen 52 and 96. The Witness test protocol was changed by the manufacturer midway through the study, and the newer version of this test kit arrived containing a package insert alerting the user to a change in procedure, which purportedly resulted in improved sensitivity. PetChek was significantly more sensitive than all other tests except DiroCHEK and the new version of Witness. DiroCHEK was significantly more sensitive than all tests except PetCheck, SNAP and the new version of Witness. Snap was more sensitive than AbboScreen and the old version of Witness. Differences in specificity were not significant (P>0.05).

Animals↗

PubMed2001

Agouti-related protein is a mediator of diabetic hyperphagia.

To explore the role of agouti-related protein (AGRP) in diabetic hyperphagia changes in hypothalamic AGRP mRNA levels were examined in diabetic rats. Rats rendered diabetic by streptozotocin displayed marked hyperglycemia (blood glucose 456.0+/-8.4 mg/dl versus 71.8+/-1.9 mg/dl) and hyperphagia (36.9+/-1.0 g/day versus 22.0+/-0.4 g/day), that was associated with a 286.6+/-4.4% increase in hypothalamic AGRP mRNA and a 178.9+/-13.5% increase in hypothalamic NPY mRNA. Insulin treatment of diabetic rats partially corrected blood glucose (147.4+/-13.1 mg/dl) and ameliorated hyperphagia (26.6+/-2.0 g/day). Insulin replacement was also associated with a return of hypothalamic AGRP mRNA (111.7+/-8.3% of controls) and NPY mRNA (125.0+/-8.9% of controls) from the elevated levels that were observed in untreated diabetic rats. In contrast to insulin treated rats, sodium orthovanadate treated diabetic rats remained significantly hyperglycemic (361.5+/-12.5 mg/dl). However, despite their persistent hyperglycemia, orthovanadate treated diabetic rats were still observed to have a significant reduction of hypothalamic AGRP mRNA (138.7+/-11.4%) and NPY mRNA (129.9+/-9.8%). Simultaneous measurement of serum leptin revealed suppressed levels in both untreated diabetic (0.5+/-0.1 ng/ml) and sodium orthovanadate treated rats (0.5+/-0.1 ng/ml) compared to non-diabetic controls (2.1+/-0.1 ng/ml). These data indicate that AGRP is a mediator of diabetic hyperhpagia and suggest that insulin can directly influence hypothalamic AGRP and NPY mRNA expression.

Agouti-Related Protein↗

PubMed2001

A knowledge-based, concept-oriented view generation system for clinical data.

Information overload is a well-known problem for clinicians who must review large amounts of data in patient records. Concept-oriented views, which organize patient data around clinical concepts such as diagnostic strategies and therapeutic goals, may offer a solution to the problem of information overload. However, although concept-oriented views are desirable, they are difficult to create and maintain. We have developed a general-purpose, knowledge-based approach to the generation of concept-oriented views and have developed a system to test our approach. The system creates concept-oriented views through automated identification of relevant patient data. The knowledge in the system is represented by both a semantic network and rules. The key relevant data identification function is accomplished by a rule-based traversal of the semantic network. This paper focuses on the design and implementation of the system; an evaluation of the system is reported separately.

Artificial Intelligence↗

PubMed2001

Toward a representation format for sharable clinical guidelines.

Clinical guidelines are being developed for the purpose of reducing medical errors and unjustified variations in medical practice, and for basing medical practice on evidence. Encoding guidelines in a computer-interpretable format and integrating them with the electronic medical record can enable delivery of patient-specific recommendations when and where needed. Since great effort must be expended in developing high-quality guidelines, and in making them computer-interpretable, it is highly desirable to be able to share computer-interpretable guidelines (CIGs) among institutions. Adoption of a common format for representing CIGs is one approach to sharing. Factors that need to be considered in creating a format for sharable CIGs include (i) the scope of guidelines and their intended applications, (ii) the method of delivery of the recommendations, and (iii) the environment, consisting of the practice setting and the information system in which the guidelines will be applied. Several investigators have proposed solutions that improve the sharability of CIGs and, more generally, of medical knowledge. These approaches can be useful in the development of a format for sharable CIGs. Challenges in sharing CIGs also include the need to extend the traditional framework for disseminating guidelines to enable them to be integrated into practice. These extensions include processes for (i) local adaptation of recommendations encoded in shared generic guidelines and (ii) integration of guidelines into the institutional information systems.

Computer Simulation↗

PubMed2001

Clinical study on the treatment of 325 cases of atrioventricular node reentrant tachycardia by radiofrequency catheter ablation.

In order to improve the efficacy of modified inferior method or middle method of radiofrequency catheter ablation (RFCA) in the treatment of atrioventricular node reentrant tachycardia (AVNRT), the clinical data of 325 cases of AVNRT from March 1992 to Feb. 2000 being subjected to the treatment of RFCA were retrospectively analyzed. The results showed that the successful rate was increased and recurrence was decreased year by year. In the recent 4 years the effective rate was up to 100%. The complication of three grade of AVB occurred in 3% and recurrent rate in 9.1% before March 1996, but both of them were zero in the last 3 years. The time of RFCA procedure and X-ray exposure was significantly reduced. It was concluded that ablating more than 3 targets by modified inferior method or middle method with energy titrating and strict endpoint was the crux of obtaining satisfactory therapeutic effects and preventing recurrence.

Adolescent↗

PubMed2001

A multicenter, randomized, controlled trial to evaluate the safety profile, tolerability, and efficacy of rofecoxib in advanced elderly patients with osteoarthritis.

This 6-week study was conducted to test the efficacy, safety, and tolerability of rofecoxib (a selective COX-2 inhibitor) compared to nabumetone (a non-selective NSAID) and placebo in osteoarthritis (OA) patients aged 80 and older. Three hundred forty-one patients, mean age 83 years, were randomized. Allocations were made in an approximately 1:2:1:2 ratio (placebo: 12.5 mg rofecoxib: 25 mg rofecoxib: 1500 mg nabumetone). Least square mean changes from baseline in the primary efficacy endpoint, Patient Global Assessment of Disease Status, were as follows (with negative numbers indicating improvement): -14.85 mm for placebo; -25.34 mm for 12.5 mg rofecoxib; -25.40 mm for 25 mg of rofecoxib; and -25.95 mm for nabumetone (p<0.001 for all active treatments vs placebo.) Results from secondary endpoints, including the 3 WOMAC sub-scales (pain, stiffness, and disability) and the Investigator Global Assessment of Disease Status, were consistent with those for the primary endpoint. No significant between-group differences were observed in the proportions of patients who discontinued treatment due to either clinical or laboratory adverse experiences. Renal safety (edema and hypertension adverse experiences) was similar for rofecoxib and nabumetone. No gastroduodenal ulcers occurred; however, the demonstration of gastrointestinal risk with rofecoxib or nabumetone was beyond the scope of this trial. We conclude that in patients 80 years and older, rofecoxib, 12.5 mg and 25 mg once daily, demonstrated clinical efficacy for the treatment for OA as did 1500 mg of nabumetone. Rofecoxib and nabumetone were generally well tolerated in this elderly population.

Aged↗

PubMed2001

Fungi and humans: closer than you think.

The budding yeast, Saccharomyces cerevisiae, has long been used as a model system to study the functions of human genes. Now that the genome sequences from several other fungal species are nearly complete, we can characterize the genetic diversity in the fungal kingdom at the genomic level. This diversity means that the number of human genes with homologues in the fungal kingdom is double that with homologues in S. cerevisiae only. Therefore, functional studies of human genes in the fungal model systems should look beyond S. cerevisiae.

Fungal Proteins↗

PubMed2001

Regulation of death receptor expression and TRAIL/Apo2L-induced apoptosis by NF-kappaB.

TRAIL (tumour-necrosis factor-related apoptosis ligand or Apo2L) triggers apoptosis through engagement of the death receptors TRAIL-R1 (also known as DR4) and TRAIL-R2 (DR5). Here we show that the c-Rel subunit of the transcription factor NF-kappaB induces expression of TRAIL-R1 and TRAIL-R2; conversely, a transdominant mutant of the inhibitory protein IkappaBalpha or a transactivation-deficient mutant of c-Rel reduces expression of either death receptor. Whereas NF-kappaB promotes death receptor expression, cytokine-mediated activation of the RelA subunit of NF-kappaB also increases expression of the apoptosis inhibitor, Bcl-xL, and protects cells from TRAIL. Inhibition of NF-kappaB by blocking activation of the IkappaB kinase complex reduces Bcl-x L expression and sensitizes tumour cells to TRAIL-induced apoptosis. The ability to induce death receptors or Bcl-xL may explain the dual roles of NF-kappaB as a mediator or inhibitor of cell death during immune and stress responses.

Animals↗

PubMed2001

Genome sequence and comparative analysis of the solvent-producing bacterium Clostridium acetobutylicum.

The genome sequence of the solvent-producing bacterium Clostridium acetobutylicum ATCC 824 has been determined by the shotgun approach. The genome consists of a 3.94-Mb chromosome and a 192-kb megaplasmid that contains the majority of genes responsible for solvent production. Comparison of C. acetobutylicum to Bacillus subtilis reveals significant local conservation of gene order, which has not been seen in comparisons of other genomes with similar, or, in some cases closer, phylogenetic proximity. This conservation allows the prediction of many previously undetected operons in both bacteria. However, the C. acetobutylicum genome also contains a significant number of predicted operons that are shared with distantly related bacteria and archaea but not with B. subtilis. Phylogenetic analysis is compatible with the dissemination of such operons by horizontal transfer. The enzymes of the solventogenesis pathway and of the cellulosome of C. acetobutylicum comprise a new set of metabolic capacities not previously represented in the collection of complete genomes. These enzymes show a complex pattern of evolutionary affinities, emphasizing the role of lateral gene exchange in the evolution of the unique metabolic profile of the bacterium. Many of the sporulation genes identified in B. subtilis are missing in C. acetobutylicum, which suggests major differences in the sporulation process. Thus, comparative analysis reveals both significant conservation of the genome organization and pronounced differences in many systems that reflect unique adaptive strategies of the two gram-positive bacteria.

Amino Acid Sequence↗

PubMed2001

Catabolic effects of continuous human PTH (1--38) in vivo is associated with sustained stimulation of RANKL and inhibition of osteoprotegerin and gene-associated bone formation.

Continuous infusion of PTH in vivo results in active bone resorption. To investigate the molecular basis of the catabolic effect of PTH in vivo, we evaluated the role of OPG and RANKL, which are known to influence osteoclast formation and function. Weanling rats fed a calcium-free diet were parathyroidectomized and infused with PTH via an Alzet pump to examine: 1) the changes of serum-ionized calcium and osteoclast number, 2) the expression of OPG/RANKL mRNA and protein, and 3) the expression of osteoblast phenotype bone formation-associated genes such as osteoblast specific transcription factor, osteocalcin, bone sialoprotein, and type I collagen. PTH (1--38) (0.01--20 microg/100 g) continuous infusion for 1--24 h resulted in a dose-dependent increase in serum-ionized calcium in parathyroidectomized rats and a corresponding dose-dependent increase in osteoclast number, indicating an increased bone resorption. At 20 microg/100 g PTH dose level, serum-ionized calcium was 2.1-fold of the vehicle control and not different from the Sham-parathyroidectomized rats, and osteoclast number was 3-fold of the vehicle control and 1.7-fold of the Sham-parathyroidectomized rats. In the distal femur, RANKL mRNA expression was increased (27-fold) and OPG mRNA expression was decreased (4.6-fold). The changes in RANKL and OPG mRNA levels were rapid (as early as 1 h), dose dependent, and sustained over a 24-h period that was examined. Immunohistochemical evaluation of bone sections confirmed that OPG level was reduced in proximal tibial metaphysis upon PTH infusion. Circulating OPG protein level was also decreased by 32% when compared with the parathyroidectomized control. The expression of genes that mark the osteoblast phenotype was significantly decreased [osteoblast specific transcription factor (2.3-fold), osteocalcin (3-fold), bone sialoprotein (2.8-fold), and type I collagen (5-fold)]. These results suggest that the catabolic effect of PTH infusion in vivo in this well-established resorption model is associated with a reciprocal expression of OPG/RANKL and a co-ordinate decrease in the expression of bone formation-related genes. We propose that the rapid and sustained increase in RANKL and decrease in OPG initiate maintain and favor the cascade of events in the differentiation/recruitment and activation of osteoclasts.

Animals↗

PubMed2001

[Malformed macrocephalous sperm with polytails and chromosomal aberrance].

OBJECTIVE: To investigate the relationship between sperm anomalies and chromosomal aberrance and to further understand the pathological changes of anomalous spermatozoa. METHODS: Light and electronic (SEM or TEM) microscopes were used for morphological analysis. Fluorescence in situ hybridization(FISH) with chromosome X-, Y-specific probes were used for aneuploidy detection in sperms of the patient. RESULTS: Ninety eight point seven five per cent of the Papanicolaou stained sperms were observed to be abnormal; 100% of the sperm heads were abnormal, measured under oil objective (1000 times); 60.25% of the sperms had two or more tails (the maximum being eight tails). SEM and TEM demonstrated that the heads contained a large amount of cytoplasmic structure, the surfaces of heads were uneven, the nuclei were of much irregular shape; besides aberrance in quantity, anomalies occurred with centromeres, mitochondria and flagella in the tails. The results of FISH showed that the aneuploidy rate of sex chromosomes was 61.41% which was parallel to the rate of polytails. CONCLUSION: Even though the chromosomes in somatic cells are normal, the chromosomes in anomalous sperms may be abnormal.

Adult↗

PubMed2001

[Study on frequencies of aneuploidy in mouse oocyte and female pronucleus of one cell zygote induced by benzene].

OBJECTIVE: To study the effect of benzene on aneupoidy of oocytes and female pronucleus of one cell zygotes. METHOD: The NIH adult female mice were treated with varies doses of benzene (942, 1,881 and 3,762 mg/kg respectively) via single gavage and (706, 1,922 and 4,864 mg/m3, respectively) multiple inhalation. After gavage, the mice were pair-matched (1:1) with males overnight. The ovulated oocytes and the one cell zygotes were collected for cytogenetic analysis and the frequencies of aneuploidy were detected. RESULTS: The frequencies of aneuploid in M II oocytes significantly increased in the three groups treated with inhalation (7.06%, 7.50% and 7.76%, respectively, control group 0.00%, P < 0.05) of benzene, as compared with those in the control group (1.30%), with a dose-dependent response. Meiotic delay of M I oocytes was observed, with the frequency of M I oocytes of 1.16%, 3.61% and 5.75%, respectively, P < 0.05, in a dose-dependent response, too. In gavage treatment group, increase in frequency of M II oocyte aneuploidy was only observed in the high-dose group, and aneupliody frequency of female pronucleus in one cell zygotes was not induced. CONCLUSION: Exposure to high-dose benzene via gavage or inhalation was able to induce increase in aneuploidy frequency of M II oocytes in mice.

Aneuploidy↗

PubMed2001

[Does response of rape to La and critical concentration of La in red earth].

The effects of different concentration of La added in red soil on the growth, yield, content of chlorophyll and peroxidase(POD) activity of rape were studied by pot experiments. The results showed that the growth and yield of rape could be improved by low concentration of La3+, however there was no significant difference between the treatment and the control, and inhibited when the dose were more than 300 mg kg-1 and killed after 600 mg.kg-1 La was added. The decrease of chlorophyll content and chlorophyll a/b was observed when the exogenous concentration of La was more than 15 mg.kg-1. POD activity increased gradually with increasing concentration and prolonging reaction. The feasible application level of La was suggested to be below 15 mg.kg-1.

Chlorophyll↗

PubMed2001

Patient and clinician vocabulary: how different are they?

Consumers and patients are confronted with a plethora of health care information, especially through the proliferation of web content resources. Democratization of the web is an important milestone for patients and consumers since it helps to empower them, make them better advocates on their own behalf and foster better, more-informed decisions about their health. Yet lack of familiarity with medical vocabulary is a major problem for patients in accessing the available information. As a first step to providing better vocabulary support for patients, this study collected and analyzed patient and clinician terms to confirm and quantitatively assess their differences. We also analyzed the information retrieval (IR) performance resulting from these terms. The results showed that patient terminology does differ from clinician terminology in many respects including misspelling rate, mapping rate and semantic type distribution, and patient terms lead to poorer results in information retrieval.

Humans↗