Biomedical subjects

K Ye

Publications and source records attributed to K Ye.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Effect of qiongyugao on the action of DDP in inhibiting the division of GLC-82 cell strain in vitro].

OBJECTIVE: To observe the effect of Qiongyugao (QYG) on the action of DDP in inhibiting the division of GLC-82 cell strain in vitro. METHODS: The method of serum pharmacology was used in observing the morphological change of the cancer cells. By accounting the number of the live cells of each day during 6 days respectively, the growth curve was drawn up. The effects of the three groups on the cancer cells apoptosis of GLC-82 cell strain were analysed by FACS. RESULLTS: The growth of the cancer cells in control group (normal saline) was much better than the other two groups; in chemical therapy group (DDP), the number of the live cells almost kept steady; the number of the live cells in combined group(DDP plus QYG) became even lower. QYG could enhance the action of DDP in inducing the apoptosis of GLC-82 cells strain remarkably. CONCLUSION: QYG can enhance the effects of chemotherapy in inhibiting cancer cells division and inducing their apoptosis.

Adenocarcinoma↗

PubMed1999

Protein 4.1N binding to nuclear mitotic apparatus protein in PC12 cells mediates the antiproliferative actions of nerve growth factor.

Protein 4.1N is a neuronal selective isoform of the erythrocyte membrane cytoskeleton protein 4.1R. In the present study, we demonstrate an interaction between 4.1N and nuclear mitotic apparatus protein (NuMA), a nuclear protein required for mitosis. The binding involves the C-terminal domain of 4.1N. In PC12 cells treatment with nerve growth factor (NGF) elicits translocation of 4. 1N to the nucleus and promotes its association with NuMA. Specific targeting of 4.1N to the nucleus arrests PC12 cells at the G1 phase and produces an aberrant nuclear morphology. Inhibition of 4.1N nuclear translocation prevents the NGF-mediated arrest of cell division, which can be reversed by overexpression of 4.1N. Thus, nuclear 4.1N appears to mediate the antiproliferative actions of NGF by antagonizing the role of NuMA in mitosis.

Animals↗

PubMed1999

Comparison of stance time and velocity as control variables in force plate analysis of dogs.

OBJECTIVE: To investigate effects of the use of stance time or velocity as control variables on ground reaction forces in lame dogs. ANIMALS: 12 dogs with pelvic osteotomies. PROCEDURE: Data for ground reaction forces were obtained preoperatively and at 2, 4, 6, 8, 12, 16, 20, 24, and 28 weeks postoperatively, using velocity and stance time as control variables. Ground reaction forces obtained were compared between the 2 methods of data collection, as were velocities and stance times of the trials. RESULTS: Significant differences in ground reaction forces were not found between the use of velocity or stance time as a control variable at any time. Also, significant differences in stance times or velocities were not found between the 2 methods of data collection. Greatest variation in stance time and velocity was found during periods of greatest lameness. CONCLUSIONS AND CLINICAL RELEVANCE: Use of stance time as a control variable in force plate analysis does not lead to significantly different results from use of velocity as a control variable, indicating that either method may be used in force plate analysis of dogs.

Animals↗

PubMed1998

Opium alkaloid noscapine is an antitumor agent that arrests metaphase and induces apoptosis in dividing cells.

An alkaloid from opium, noscapine, is used as an antitussive drug and has low toxicity in humans and mice. We show that noscapine binds stoichiometrically to tubulin, alters its conformation, affects microtubule assembly, and arrests mammalian cells in mitosis. Furthermore, noscapine causes apoptosis in many cell types and has potent antitumor activity against solid murine lymphoid tumors (even when the drug was administered orally) and against human breast and bladder tumors implanted in nude mice. Because noscapine is water-soluble and absorbed after oral administration, its chemotherapeutic potential in human cancer merits thorough evaluation.

Animals↗

PubMed1997

Comparative calibration without a gold standard.

Comparative calibration is the broad statistical methodology used to assess the calibration of a set of p instruments, each designed to measure the same characteristic, on a common group of individuals. Different from the usual calibration problem, the true underlying quantity measured is unobservable. Many authors have shown that this problem, in general, does not have a unique solution. Most commonly used assumptions to obtain a unique solution are (i) one instrument is the gold standard (that is, unbiased) and (ii) the measurement errors of the p instruments are independent. Such constraints, however, may not be valid for many clinical applications, for example, the universal standardization project for dual X-ray absorptiometry (DXA) scanners. In this paper, we propose a new approach to resolve the comparative calibration problem when a gold standard is unavailable. Instead of the usual assumptions, we use external information in addition to data from the p instruments, to solve the problem. We address statistical estimation, hypothesis testing and missing data problems. We apply the new method specifically to the universal standardization project data where a group of individuals have been measured for bone mineral density (BMD) by three DXA scanners. We compare the results of the new method to currently used methods and show that they have better statistical properties.

Absorptiometry, Photon↗

PubMed1997

Metabolic flux distributions in recombinant Saccharomyces cerevisiae during foreign protein production.

A stoichiometric flux balancing analysis was applied to the recombinant yeast cultivation to examine the cellular physiology and relationship between the production of heterologous protein and metabolic fluxes. The fluxes in the metabolic pathway within a recombinant S. cerevisiae grown on galactose alone or mixtures of galactose and ethanol medium were calculated. It is found that an amplification of the PP (Pentose Phosphate) pathway activity resulted in an improvement of the foreign protein expression and cell yield on ATP. The carbon source used for biosynthesis from TCA cycle in the exponential growth phase was 2 and 5-fold higher, respectively, as compared with that in the late exponential growth phase and stationary phase in batch culture with galactose minimum medium. The metabolism of ethanol together with galactose in the recombinant cell looks like increasing the flux from Acetyl-CoA to TCA cycle, and amplifying the flux directing the synthesis of various kinds of precursors such as amino acids and nucleic acid which are necessary for production of a foreign protein. Metabolic flux distribution analysis also shows that the ATP synthesis rate under substrate-level phosphorylation in the mixed carbon source cultivation was lower than that in the sole carbon source (galactose) during the expression of foreign protein. However, the total ATP production rate was higher in the mixed carbon source cultivation.

Adenosine Triphosphate↗

PubMed1996

Three distinct promoters direct transcription of different 5' untranslated regions of the human interleukin 1 type I receptor: a possible mechanism for control of translation.

The 5' untranslated regions (UTR) of the human interleukin 1 (IL-1) type I receptor (IL-1RI) are encoded by one common exon (exon 2) but one of three distinct exons 1 (termed exon 1A, 1B, and 1C). These exons span approximately 50 Kb of genomic DNA. Exons 1A and 1B have multiple transcriptional initiation sites, whereas the promoter for exon 1C uses a single start site. There are no "TATA' or "CAAT' boxes, indicating that these promoters belong to the family of housekeeping gene promoters. Computer sequence analysis of exons 1A, 1B, and 1C predicts the potential to form stable secondary structures (delta G degrees 1A = -72.2 Kcal/mol, delta G degrees 1B = -125.8 Kcal/mol, delta G degrees 1C = -255.4 Kcal/mol). Exon 1C appears to be the most stable whereas exon 1A would yield a mRNA species more likely to be translated than those derived from exon 1B or 1C. The 5' UTR of exon 1C is also rich (75%) in GC which might inhibit expression. Therefore, we studied the effect of exon 1C on chloramphenicol acetyltransferase (CAT) activity. Deletion of 183 or 296 base pairs from this GC rich region was shown to increase CAT activity. In addition, insertion of a GC-rich fragment of exon 1C inhibited CAT activity driven by SV40 promoter. These results suggest that the 5' UTR exon 1C of the human IL-1RI may exert a suppressive effect on the translation of IL-1RI transcripts.

Base Sequence↗

PubMed1996

Repeated recurrence of osteosarcoma treated by resections and chemotherapy.

This paper presents 5 patients with repeated recurrence of osteosarcoma (RROS). The primary focus of 3 patients were in the distal portion of femur, and 2 patients were in the proximal portion of tibia. Three patients, whose chest X ray film were negative, were treated by amputation and chemotherapy. Two patients had isolated metastatic focus 1.5 cm in diameter in lung, were treated by amputation after 1 week of chemotherapy and then treated by lobectomy after 2 weeks of chemotherapy. After operation, the chemotherapy was carried out for 3 courses of treatment. The roentgenogram of chest and affected limb were taken once every two months. There were metastatic focuses found in the lung of 1 patient and in the distal portion of femur of 2 patients. One patient was operated on for 4 times. Up to now, 3 patients have been living for 5 years and 2 patients for 6 years after operation.

Adolescent↗

PubMed1995

[Comprehensive evaluation of protective measures in electric welding].

Protective effects of safety masks, eyewear, work clothes, gloves, periodically physical examination system, and ventilation and barriers at workplace, were evaluated by one-way analysis for handtorch welding, carbon dioxide gas-protective welding, and argon-arc welding operations, etc. in township and village enterprises and state-owned enterprises by interviewing managers in the departments of technology and work safety and field investigating. Based on the results of one-way analysis of protective measures, comprehensive evaluations of various enterprises were made with a fussy mathematical model. Both enterprises in township and village level and of state-owned were graded as A on a basis of the evaluation, which will be helpful to the better management of occupational health in the future.

Evaluation Studies as Topic↗

PubMed1994

Differential gene expression for IL-1 receptor antagonist, IL-1, and TNF receptors and IL-1 and TNF synthesis may explain IL-1-induced resistance to infection.

IL-1 pretreatment prolongs survival in lethal infection in normal and in neutropenic mice. We investigated whether this protection occurs by interference with deleterious cytokine effects. The effect of IL-1 pretreatment on concentrations of IL-1 alpha, IL-1 beta, IL-6, and TNF-alpha circulating in vivo and the ex vivo cytokine production capacity of macrophages was assessed in uninfected, non-neutropenic and neutropenic Swiss mice, in Swiss mice infected with Klebsiella pneumoniae (non-neutropenic mice) or Pseudomonas aeruginosa (neutropenic mice), and in neutropenic C3H/HeN and C3H/HeJ mice infected with P. aeruginosa. In Swiss and C3H/HeN mice, IL-1 pretreatment enhanced survival and reduced circulating TNF-alpha and IL-6 as well as LPS-stimulated production of IL-1 alpha and TNF-alpha. In C3H/HeJ mice, a lack of IL-1-induced protection was associated with low cytokine concentrations and production. In contrast, up-regulation of mRNA for the IL-1 receptor antagonist (IL-1Ra) was observed in several organs of IL-1-pretreated mice, suggesting that IL-1Ra could attenuate deleterious IL-1 effects. In addition, IL-1 pretreatment down-regulated steady state mRNA for the type I IL-1R and the type I TNFR in several organs at the time of infection, suggesting desensitization of target cells as an additional mechanism of IL-1-induced protection. We conclude that the IL-1-induced protection is at least partially mediated by down-regulating cytokine production, and that the induction of IL-1Ra and the desensitization of target cells by receptor down-modulation may also contribute to this phenomenon.

Animals↗

PubMed1994

Interleukin-1 receptor type I mRNA in mouse brain as affected by peripheral administration of bacterial lipopolysaccharide.

Following administration of endotoxin in vivo, alterations of interleukin-1 (IL-1) receptor binding have been reported. In order to assess in vivo regulation of IL-1 receptor gene expression in brain, mRNA levels for IL-1 receptor type I were measured after peripheral administration of bacterial lipopolysaccharide in mice. When 25 micrograms of lipopolysaccharide were administered intraperitoneally, IL-1 receptor type I mRNA in the brain was increased after 3 h. After 20 h, the level was diminished. This result suggests that bacterial lipopolysaccharide affects regulation of IL-1 receptor type I mRNA expression in mouse brain.

Animals↗

PubMed1994

Efficient fuzzy control strategies for the application of pH-stat to fed-batch cultivation of genetically engineered Escherichia coli.

In the cultivation of genetically engineered Escherichia coli it is very important to control the substrate concentration at an appropriate level in order to avoid the accumulation of acetate, thereby elevating the expression level of plasmid-encoded protein. In this paper, a pH-stat mode of fuzzy control was considered for the overexpression of beta-galactosidase in the fed-batch cultivation of recombinant E. coli. In the simple pH-stat fuzzy control, the response of pH change in the culture broth to the feeding rate of glucose was used to estimate the glucose consumption rate. In the modified pH-stat fuzzy control, the glucose consumption rate was accurately estimated by using pH change and the change in the carbon dioxide content of the exhaust gas. With this control strategy, the cell density could be increased to 72 g DCW dm-3, which was twofold higher than that attained in the cultivation with the simple pH-stat fuzzy control. The bulk beta-galactosidase concentration was increased to 4150 U cm-3, which was threefold higher than when the simple pH-stat control was used.

Carbon Dioxide↗

PubMed1994

Genetic susceptibility markers in Danish patients with type 1 (insulin-dependent) diabetes--evidence for polygenicity in man. Danish Study Group of Diabetes in Childhood.

Fifty-five Danish families with two offspring concordant for type 1 diabetes--identified through a nationwide population-based survey, and 57 "true sporadic" cases--matched with familial cases for age at onset, but with no IDDM-affected first-degree relatives and long disease duration, and 110 control subjects were typed for putative genetic susceptibility markers for type 1 diabetes identified from a pathogenetic model. The markers included MHC class I, II and III loci, the manganese superoxide dismutase (MnSOD) locus (chr. 6q), interleukin-1 beta (IL1B), the IL-1 receptor antagonist (IL1RN), and the IL-1 type 1 receptor (IL1RI) loci (each chr. 2q). No significant differences between familial and sporadic cases were found within the MHC region (including the following loci: HLA-DQ, -DR, heat shock protein (HSP) 70, tumour necrosis factor (TNF), HLA-B and -A). In both groups of patients 11% were negative for both DQA1*0301-DQB1*0302 and DQA1*0501-DQB1*0201 genotypes, and 7% of the type 1 diabetics had genotypes unable to encode a susceptibility DQ alpha beta heterodimer. Disease association was found for the IL1RN (p = 0.04) and for the IL1RI (p = 0.03). When comparing controls and only familial cases with type 1 diabetes for the IL1RN polymorphism a difference was observed (p = 0.003). For the IL1B RFLP a trend for difference was observed between familial cases and control subjects (p = 0.046), whereas no differences between sporadic cases and control subjects could be demonstrated neither at the IL1B nor at the IL1RN loci. A difference in the MnSOD pattern was observed between sporadic cases and controls (p = 0.04).

Adolescent↗

PubMed1993

Hematologic and immunomodulatory effects of an interleukin-1 receptor antagonist coinfusion during low-dose endotoxemia in healthy humans.

Endotoxin is a component of gram-negative bacteria that causes hematologic and immunologic changes through its induction of cytokines. Interleukin-1 receptor antagonist (IL-1Ra) is a naturally occurring inhibitor of IL-1 that competes with IL-1 for occupancy of cell-surface receptors but possesses no agonist activity. We investigated the ability of human recombinant IL-1Ra to block the effects of low-dose endotoxin. Fourteen healthy male volunteers between 18 and 30 years old were injected intravenously with 3 ng/kg Escherichia coli endotoxin. Concurrent with the injections, nine volunteers received a 3-hour continuous intravenous infusion of IL-1Ra. The other five subjects were given a 3-hour infusion of saline. Volunteers injected with endotoxin experienced a threefold increase in circulating neutrophils over baseline. This neutrophilia was significantly reduced by 48% in subjects administered endotoxin plus IL-1Ra (P = .0253). Ex vivo mitogen-induced peripheral blood mononuclear cell proliferation decreased by greater than 60% at 3 and 6 hours after endotoxin injection (P = .0053). This endotoxin-induced reduction in mitogen response was reversed in subjects coinjected with IL-1Ra (P = .0253). Endotoxin-induced symptoms, fever, and tachycardia were unaffected by IL-1Ra. IL-1 appears to be an important mediator in endotoxemia because some of its hematologic and immunomodulatory effects can be blocked by IL-1Ra.

Adolescent↗

PubMed1993

Intravenous endotoxin suppresses the cytokine response of peripheral blood mononuclear cells of healthy humans.

When administered parenterally, endotoxin stimulates the synthesis of IL-1, TNF-alpha, and IL-6. However, this initial injection induces tolerance; a second injection of endotoxin results in lower levels of circulating cytokines. In our study, five healthy male volunteers between the ages of 18 and 30 were injected with Escherichia coli endotoxin. Four subjects received only saline. Immediately before the injection and 3, 6, and 24 h afterward, PBMC were isolated and stimulated in vitro with endotoxin, IL-1, or toxic shock syndrome toxin-1. Inasmuch as CD14+ monocytes are the primary source of the cytokines induced by these stimuli, results are expressed as cytokine production per 10(6) CD14+ cells. Six h after endotoxin injection, endotoxin-stimulated CD14+ cells synthesized 66% less IL-1 beta (p < 0.01), 47% less TNF-alpha (p < 0.001), 56% less IL-6 (p < 0.01), and 49% less IL-8 (p < 0.01) than cells obtained before the injection. This suppression was not specific for endotoxin; IL-1 beta-induced IL-1 alpha and TNF-alpha were reduced by 84% (p = 0.01) and 68% (p < 0.001), respectively. A decrease in cytokine synthesis was also observed using toxic shock syndrome toxin-1 as a stimulus: 57% for IL-1 beta (p = 0.06), 70% for TNF-alpha (p < 0.01), 56% for IL-6 (p < 0.05), and 71% for IL-8 (p = 0.001). When data were expressed as cytokine production per 10(6) PBMC, cells isolated 3 h after endotoxin injection synthesized significantly less stimulus-induced IL-1, TNF-alpha, IL-6, and IL-8 than did PBMC from saline-injected controls. We conclude that endotoxin tolerance is due, in part, to changes in the stimulus-induced cytokine response of circulating CD14+ cells.

Antigens, CD↗

PubMed1993

Identification of the promoter region of human interleukin 1 type I receptor gene: multiple initiation sites, high G+C content, and constitutive expression.

To better understand the role of interleukin 1 (IL-1) and its receptor in disease, we have isolated a genomic clone of the human IL-1 type I receptor and have identified the promoter region. There are multiple transcriptional initiation sites as demonstrated by primer extension. DNA sequence analysis shows that the promoter region contains neither a TATA nor a CAAT box; however, the 5' upstream regulatory elements contain two AP-1-like binding sites. The internal regulatory sequences found immediately downstream to the 5' transcriptional start site contain four Sp1 binding domains and have a high G+C content of 75%. This portion of the 5' untranslated region of the mRNA can form stable secondary structure as predicted by computer modeling. Base pairs -4 to + 10 share striking resemblance to an initiator sequence that directs basal expression of certain TATA-less genes-e.g., terminal deoxynucleotidyltransferase in lymphocytes. The IL-1 receptor promoter directs basal expression of chloramphenicol acetyltransferase in transiently transfected cells. Overall, the promoter of the IL-1 type I receptor gene resembles that of constitutively expressed genes that have housekeeping- and/or growth-related functions. The constitutive nature of the promoter may account for this gene being expressed at low levels in diverse cell types. Our finding sheds more understanding into the mechanisms governing the regulation of the IL-1 receptor in health and disease.

Base Composition↗

PubMed1992

Interleukin 4 (IL) 4 up-regulates gene and surface IL 1 receptor type I in murine T helper type 2 cells.

The T cell-derived cytokine interleukin (IL) 4 is known to increase the proliferative response of T cells stimulated with IL 1. IL 4 is also an autocrine growth factor for type II T helper cells (Th2) cells. In the present studies, we examined the effect of murine recombinant IL 4 on the expression of the IL 1 receptor type I (IL 1RtI) in murine Th2 cell lines at the mRNA and surface level. Using a specific anti-murine IL 1RtI monoclonal antibody and flow microfluorometry, we found that IL 4 increased the surface expression of IL 1RtI in a dose-dependent manner. In D10S cells, a subline of the Th2 cell line D10.G4.1, 50-500 pg/ml IL 4 up-regulated the receptor 1.8- to 3.2-fold (p less than 0.05). This up-regulation was also seen at the mRNA level. The effect was not due to increased stability of the mRNA, since IL 4 did not modify the half-life of IL 1RtI mRNA. IL 4 also up-regulated IL 1RtI on CDC25 cells, another Th2 cell line. However, we did not observe an effect of IL 4 on gene expression of IL 1RtI in BALB/c 3T3 fibroblasts. IL 2 and IL 4 showed an additive effect in up-regulating IL 1RtI and D10S cells. These studies indicate that IL 4 up-regulates IL 1RtI in murine Th2 cells by increasing gene expression for IL 1RtI without affecting mRNA stability. Thus, IL 4 production by Th2 cells may amplify the immune response via up-regulation of IL 1RtI.

Animals↗

PubMed1992

Interleukin-1 down-regulates gene and surface expression of interleukin-1 receptor type I by destabilizing its mRNA whereas interleukin-2 increases its expression.

The interleukin-1 receptor type I (IL-1RtI) plays an important role in the biological effects of IL-1, but regulation of its surface and gene expression remains unknown. We found that occupancy of 2-15% of the IL-1 surface receptor results in dramatic down-regulation of IL-1RtI both at the mRNA and cell surface level in murine D10S cells, a subline of T-helper type 2 cells. At these low occupancy levels (3 x 10(-12) to 3 x 10(-13) M), the reduction in IL-1RtI surface expression appears at 24 hr and continues to 48 and 72 hr. At the mRNA level, low occupancy of the IL-1R results in decreased IL-1RtI mRNA stability; steady state half-life of the IL-1RtI mRNA is reduced from 6 to 1 hr after exposure to 3 x 10(-12) M IL-1. This down-regulation of IL-1RtI by IL-1 is blocked by cycloheximide, suggesting de novo protein synthesis is necessary for decreased RNA stability. Low concentrations of human IL-1 beta, murine and rabbit IL-1 alpha or beta similarly down-regulated IL-1RtI, whereas low concentrations of human IL-1 alpha failed to reduce the receptor surface expression, despite inducing a full proliferative response. We also observed that the effect of IL-1 on this down-regulation was not through protein kinase C (PKC), since PMA rapidly increased IL-1RtI mRNA levels within 30 min and persisted for 24 hr. IL-2 up-regulated IL-1RtI in D10S cells at both mRNA and protein levels. These results demonstrate that low occupancy of IL-1 receptors induces down-regulation of IL-1RtI surface as well as mRNA expression. The regulation of IL-1RtI gene expression may be one of the mechanisms by which IL-1-mediated events are controlled.

Animals↗