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Biomedical subjects

Q Gao

Publications and source records attributed to Q Gao.

At least 127 records · Page 7Linked to original sources

[Bacteriological study of chronic maxillary sinusitis in adults and observation of susceptibility to antibiotics].

The unilateral mucosal samples were taken from 42 patients and were cultured for bacteria. Meanwhile, the antimicrobial susceptibility was determined for 11 antibiotics and the beta-lactamase-producing bacteria(beta LPB) were examined. In 85.71% of all samples, bacterial growth was present. Anaerobic bacteria were present in 21.43% of cases. Predominant aerobic bacteria were alpha-hemolytic streptococci and coagulase-negative staphylococci. Predominant anaerobic bacteria were peptostreptococcus species and bacteroides species. The beta LPB were isolated from 40% patients, which were responsible for the resistance to some antibiotics. The antimicrobial susceptibility testing showed that the antibiotics containing beta-lactamase inhibitor, third-generation cephalosporins and third-generation quinolones had good efficacy. Our findings indicated the bacterial infection may not play the key role in the development of chronic sinusitis and the bacterial infection may not play the key role in the development of chronic sinusitis and the resistance to some antibiotics due to the high prevalence of beta-lactamase production must be considered when the antibiotics therapy is taken.

Adult↗

[Nasal packing and packing materials chosing after ESS (with clinical analysis of 769 cases)].

Nasal packing after endoscopic sinus surgery is an important factor affecting the outcome of the operation. In order to discuss the clinical effect of no packing method and packing with different materials, we summarized our six years packing experiences of 769 cases (993 nasal cavities) undergoing ESS. The paper disclosed that if operation cavities didn't involve in middle turbinate, inferior turbinate and nasal septum, no packing method could be chosen; Otherwise, packing with different materials could be chosen, both methods could control the postoperative hemorrhage in a safe range. But in order to reducing patients' pain and operation cavities' reaction, it suggests operators had better choose no packing method or packing with absorbable hemostate gauze.

Adolescent↗

[Simultaneous determination of creatinine, pseudouridine and uric acid in serum and urine by high performance liquid chromatography].

In this paper a sensitive, rapid and simple HPLC method for the simultaneous determination of creatinine (Cr), pseudouridine (Pu) and uric acid(UA) has been established. We have evaluated clinical value of the method in the early diagnosis of diabetic nephropathy (DN). Separation was obtained using Shim-pack CLC-ODS 15 x 0.6 cm column and mobile phase of buffer solution of phosphate (pH 3.0, 0.02 mol/L) with flow rate of 1 mL/min. Detection was performed with UV detector at an automatic adjustment of wavelength. The recoveries of Cr, Pu and UA were 101.4%, 104.9% and 105.0% respectively. The calibration curves were linear within the concentration range of 8.6-274.6 mumol/L for Cr, 0.72-22.93 mumol/L for Pu and 19.1-612.7 mumol/L for UA (n = 6, r > 0.999, p < 0.01). The CV for within day and between day measurements were < 2.5% and < 5.0% respectively. In addition, Pu, Cr and UA were simultaneously determined in serum and urine of 39 patients with diabetic mellitus (DM). 15 patients with nephrotic syndrome (NS) and 53 normal subjects by the method. Results include: 1. the levels of serum Pu in all DM patients (100%) with microalbuminuria (MiAU) and macroalbuminuria (MaAU) were greater than maximum of normal subjects (X + 2S). In addition, in 9 DM patients (41%) with normal albuminuria (NAU) the levels were also greater than the maximum. 2. In patients with DM, there was no correlation between the serum Pu and the urinary albumin excretion (UAE), whereas the serum Pu correlated closely with the serum Cr. However, the incidence for serum Pu increase was significantly greater in patients. 3. The levels of serum Pu in patients with NS were greater than those in control subjects and patients with DM. Conclusion is that the determination of serum Pu could be used as sensitivity index for the early diagnosis of DN.

Chromatography, High Pressure Liquid↗

[Functional changes of forelegs of rats after C6 and C8 nerve roots resection: experimental study].

OBJECTIVE: To find new nerve roots as dynamic source, we observed the effect of C(6) and C(8) resection on the function of forelegs of roots. METHOD: Considering the relationship between C(6) and biceps brachii muscle, C(8) and flexor digitorum profundus muscle, we resected C(6) and C(8) nerve roots of right side as the experimental side and compared with the left side. The position, pace, appearance of ulcer were observed on the foot and the phenomena of self-injury were seen regularly. The EMG and tensile strength of biceps brachii and flexor digitorum profundus muscles were measured immediately at two weeks and four weeks after operation. RESULT: The position of two sides of the rats was symmetrical. There were no limp, ulceration and phenomena of self-injury. Normal wave figure in EMG was noted in the experimental side. There was no significant difference in t test in EMG wave amplitude, maximum tetanized systole tensile strength and duration of isometric contraction. CONCLUSION: C(6) and C(8) nerve roots resection has no obvious influence on function of the leg.

Animals↗

Abrogation of wild-type p53-mediated transactivation is insufficient for mutant p53-induced immortalization of normal human mammary epithelial cells.

The p53 protein has become a subject of intense interest since the discovery that about 50% of human cancers carry p53 mutations. Mutations in the p53 gene are the most frequent genetic lesions in breast cancer, suggesting a critical role for p53 protein in normal mammary epithelial cell (MEC) growth control. We previously demonstrated that abrogation of the p53 function by a cancer-derived p53 mutant, del239, was sufficient to induce immortalization of normal MECs. To further extend these findings and to examine the mechanism of mutant p53-induced immortalization of MECs, we tested the immortalizing ability of four selected p53 mutants (R175H, R248W, R249S, and R273H), which involve residues that cluster close to N239 in the three-dimensional structure and which are critical for the DNA-binding function of p53. Interestingly, two of these mutants (R175H and R249S) reproducibly immortalized 76N normal MECs, whereas the other two mutants (R248W and R273H) induced an extension of life span but not immortalization. These results further substantiate that selective ablation of p53 function with dominant-negative mutants is sufficient for immortalization of MECs. To determine whether abrogation of the transactivation function of endogenous p53 was important for the differential immortalizing ability of p53 mutants, we measured the effects of mutant p53 on the endogenous wild-type p53-mediated transactivation of a chloramphenicol acetyltransferase reporter linked to a consensus p53 binding DNA sequence in transiently transfected 76N MECs. All of the mutants, regardless of their immortalizing phenotype, abrogated the endogenous wild-type p53-mediated transactivation to a similar extent. Thus, abrogation of transactivation function is not sufficient for mutant p53-induced immortalization of normal MECs. The p53-immortalized MECs showed substantial telomerase activity; however, induction of telomerase activity occurred at late passages and was undetectable in mutant p53-expressing cells prior to immortalization. We suggest that mechanisms other than abrogation of transactivation and induction of telomerase activity determine the differential MEC-immortalizing behavior of various p53 mutants.

Breast↗

Balancing the immune system for tolerance: a case for regulatory CD4 cells.

In the past, tolerance mechanisms have focused on processes that involve elimination (deletion) or paralysis (anergy) of immune responses. It is now becoming clearer that peripheral tolerance to antigen depends on the generation of regulatory cells that function to maintain the tolerant state. The development of peripheral tolerance may require that the immune system utilize several strategies, including deletion, anergy, and immunoregulatory pathways, and these strategies may overlap. Recent investigations using animal models of transplantation tolerance have demonstrated that immunoregulatory CD4 mechanisms may play a central role in limiting organ-destructive immune responses. In this Overview, we discuss the rationale behind the need for invoking active regulatory mechanisms in peripheral immunologic tolerance and summarize the data that support or refute a CD4 regulatory mechanism.

Animals↗

Late-infantile ceroid-lipofuscinosis: lysine methylation of mitochondrial ATP synthase subunit c from lysosomal storage bodies.

Late-infantile ceroid-lipofuscinosis is a fatal autosomal recessively inherited disease characterized by massive accumulations of lysosomal storage bodies in many tissues. A major constituent of the storage bodies is the subunit c protein of mitochondrial ATP synthase. Juvenile ceroid-lipofuscinosis, a disease that is similar to but genetically distinct from the late-infantile disorder, also involves lysosomal accumulation of the subunit c protein. In the juvenile disease, the stored form of the protein contains an epsilon-N-trimethyllysine (TML) residue at position 43. Analyses were performed to determine whether subunit c protein stored in the late-infantile disease is also trimethylated at lysine residue 43. Amino acid composition analysis of the subunit c protein stored in brains from subjects with the late-infantile disease indicated that one of the two lysine residues in the protein is trimethylated. Data from molecular mass analysis of the protein was consistent with the presence of three methyl groups not present in the unmodified protein. The TML in the storage body subunit c protein was found by amino acid sequence analysis to occur exclusively at residue 43. The lysine at this position in the stored protein was completely methylated. Recent studies suggest that the subunit c protein from normal mitochondria may also have the same amino acid modification. Thus, it appears that specific methylation of lysine residue 43 of mitochondrial ATP synthase subunit c is probably a normal post-translational modification, and that the lysosomal storage of this protein in late-infantile, as well as in juvenile ceroid-lipofuscinosis, does not result from a defect in its methylation.

Cerebral Cortex↗

Determination of isatin in urine and plasma by high-performance liquid chromatography.

A method for the detection and determination of isatin (indole-2,3-dione) in urine and plasma by high-performance liquid chromatography has been developed. It consists of a two-step purification using two different columns with UV detection. With this method, we have reconfirmed that isatin is present in human urine. We have also demonstrated that isatin is present in human plasma and that the isatin levels in spot urine samples reflect the plasma isatin levels. In the present report we describe a rapid and sensitive means of determining urine and plasma isatin for laboratories equipped with a high-performance liquid chromatography system.

Adult↗

Knowledge-based model of a glucosyltransferase from the oral bacterial group of mutans streptococci.

Mutans streptococci glucosyltransferases catalyze glucosyl transfer from sucrose to a glucan chain. We previously identified an aspartyl residue that participates in stabilizing the glucosyl transition state. The sequence surrounding the aspartate was found to have substantial sequence similarity with members of alpha-amylase family. Because little is known of the protein structure beyond the amino acid sequence, we used a knowledge-based interactive algorithm, MACAW, which provided significant level of homology with alpha-amylases and glucosyltransferase from Streptococcus downei gtfI (GTF). The significance of GTF similarity is underlined by GTF/alpha-amylase residues conserved in all but one alpha-amylase invariant residues. Site-directed mutagenesis of the three GTF catalytic residues are homologous with the alpha-amylase catalytic triad. The glucosyltransferases are members of the 4/7-superfamily that have a (beta/alpha)8-barrel structure and belong to family 13 of the glycohydralases.

Algorithms↗

A genetic map of bovine chromosome 7 with an interspecific hybrid backcross panel.

A genetic linkage map of bovine Chromosome (Chr) 7 was generated with a Bos taurus x Bos gaurus interspecific hybrid backcross panel. This study included six previously mapped microsatellites and five unmapped expressed genes that were identified by PCR-based restriction fragment length variants (RFLVs). The gene order (from centromere to telomere) and the map distances (in centimorgans) are as follows: cen-BM2607-11.2-LDLR-3.6-AMH,CSF2-11. 2-BP41-19-BM6117-19-SPARC-14.4-FGFA-15.5-BM18 53-11.2-RASA-18. 8-ILSTS006. Previous comparative synteny mapping demonstrated that bovine Chr 7 shares homologous regions with both HSA5q and HSA19p. A break or fusion between AMH and CSF2 in an ancestral chromosome is suggested to account for the current arrangement of these homologous segments in the human and bovine genomes. In this study, we demonstrate that a short proximal portion of BTA7 is homologous with HSA19p, while a larger distal portion of BTA7 is homologous with human Chr 5q. The orientation of these conserved human segments on BTA7 is also demonstrated. Our data show that the linear order of genes has not been conserved within the homologous region of HSA5 and BTA7, and one chromosomal translocation or inversion is proposed to account for this difference.

Animals↗

Association between enhanced Th2/Th1 cytokine profile and donor T-cell chimerism following total lymphoid irradiation.

Total lymphoid irradiated (TLI) mice develop antigen specific tolerance if the initial antigen exposure occurs shortly after the completion of TLI. We injected TLI-treated mice with semiallogeneic donor cells at 2, 7, or 28 days after completing TLI and determined the levels of donor CD4 and CD8 cells 5 to 7 weeks after TLI treatment. The level of chimerism correlated with the timing of the initial alloantigen exposure. Donor CD4 and CD8 cells were noted only in day 2 or 7 injected mice. Because donor cell chimerism suggested increased in vivo survival of donor cells, we used the level of donor cell chimerism as a surrogate marker for tolerance to examine the relationship between the development of tolerance and enhanced Th2/Th1 cytokine responses to donor antigen. Increased levels of donor CD4 and CD8 cells in the TLI-treated mice was associated with increased Th2/Th1 cytokine production and decreased CTL activity to donor antigen in vitro. Higher Th2/Th1 cytokine levels also correlated with lower CTL activity. The results indicate that the increased production of Th2/Th1 may function to enhance survival of donor cells in TLI-treated mice and suggest that tolerance induction after TLI treatment involves immunoredirection.

Animals↗

Biological effects of the immunomodulator beta 1-3D polyglucose are strongly potentiated by conjugation to biodegradable microbeads.

It is demonstrated that the biological effects of the immunomodulator beta 1-3D polyglucose, when covalently linked to polymethacrylate or biodegradable albumin microbeads, are strongly potentiated. The potentiation is recorded as an increased protection effect of the conjugates in Escherichia coli sepsis in mice, and as increased IL-1 production by murine macrophages in vitro.

Adjuvants, Immunologic↗

Characterization and cytokine-stimulating activities of acidic heteroglycans from Tremella fuciformis.

Four acidic heteroglycans, T2a-T2d, were isolated from the body of Tremella fuciformis Berk. They contained 1.9%-2.9% of acetyl groups and were composed of mannose (Man), glucuronic acid (GlcA), and small amounts of xylose (Xyl), glucose (Glc), and fucose (Fuc). According to methylation analysis they had a mannan backbone consisting of 3-linked Man, and side chains containing glucosyl, mannosyl, fucosyl, xylosyl, and glucuronic acid residues. The side chains were attached through O-2, O-4, or O-6 in about 40 percent of backbone mannosyl residues. Molecular masses of the four polysaccharides were 410, 250, 34, and 20 kDa, respectively. T2a-T2d induced human monocytes to produce interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in vitro. The products of Smith degradation (T2a-S) and lithium degradation (T2a-L) of T2a and the product of deacetylation (T2b-D) of T2b also induced monocytes to secret IL-1 as efficiently as the original polysaccharides, indicating that xylosyl and glucuronic acid residues as well as acetyl groups were not important to promote the cytokine-stimulating activity.

Cells, Cultured↗

Assignment of the casein kinase II gene family to cattle chromosomes.

Theileriosis, or East Coast fever, a parasitic disease in cattle, is associated with overexpression of casein kinase II. Casein kinase II is composed of two catalytic subunits (alpha or alpha') and two regulatory beta subunits. The genes encoding these subunits of casein kinase II were mapped to bovine chromosomes by polymerase chain reaction analysis of a well-characterized bovine x rodent somatic hybrid cell panel. The alpha-subunit (CSNK2A1) was mapped to bovine chromosome 13, the alpha'-subunit (CSNK2A2) to chromosome 5 and the beta-subunit (CSNK2B) to chromosome 23. Both CSNK2A1 and CSNK2B mapped to known regions of conserved synteny between human and cattle, while CSNK2A2 defined a new homology segment between the human and bovine genomes.

Animals↗

Oncologic image compression using both wavelet and masking techniques.

A new algorithm has been developed to compress oncologic images using both wavelet transform and field masking methods. A compactly supported wavelet transform is used to decompose the original image into high- and low-frequency subband images. The region-of-interest (ROI) inside an image, such as an irradiated field in an electronic portal image, is identified using an image segmentation technique and is then used to generate a mask. The wavelet transform coefficients outside the mask region are then ignored so that these coefficients can be efficiently coded to minimize the image redundancy. In this study, an adaptive uniform scalar quantization method and Huffman coding with a fixed code book are employed in subsequent compression procedures. Three types of typical oncologic images are tested for compression using this new algorithm: CT, MRI, and electronic portal images with 256 x 256 matrix size and 8-bit gray levels. Peak signal-to-noise ratio (PSNR) is used to evaluate the quality of reconstructed image. Effects of masking and image quality on compression ratio are illustrated. Compression ratios obtained using wavelet transform with and without masking for the same PSNR are compared for all types of images. The addition of masking shows an increase of compression ratio by a factor of greater than 1.5. The effect of masking on the compression ratio depends on image type and anatomical site. A compression ratio of greater than 5 can be achieved for a lossless compression of various oncologic images with respect to the region inside the mask. Examples of reconstructed images with compression ratio greater than 50 are shown.

Algorithms↗

[Microwave operation of angiofibroma of nasopharynx under nasal endoscope].

Two patients with angiofibroma of nasopharynx were treated with microwave operation under nasal endoscope in our hospital. This operation could reduce the amount of blood less than operations by palatine apporach and nose apporach apprentently. So the blood transplantation was avoid. Meanwhile, it lessen somatopsychic pain and ecnomical burden. Because of the clean and clear operation field under nasal endoscope, the tumor could be removed completely and correctly. Then, the possibility of relapse was reduced.

Adolescent↗

Research on the estimate of safety and toxicity of p-nitrophenol sodium with a physiologically based pharmacokinetics model.

The safety and toxicity of chemicals given first to animals and finally to humans are generally estimated with a method of safe coefficient, which is scientifically a way lack of grounds. To make a change of the old method, we designed a Physiologically-Based Pharmacokinetics Model for the estimate of safety and toxicity of chemicals. As an example, p-nitrophenol sodium (PNP-Na) is used in the research work. Studies of the PNP-Na pharmacokinetics in bodies of rat as well as humans are made, and possibilities of making use of the Model in the estimate of safety and toxicity of chemicals are discussed.

Animals↗