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Biomedical subjects

Q Cai

Publications and source records attributed to Q Cai.

At least 37 records · Page 2Linked to original sources
PubMed2001

Point mutations of muscle mitochondrial DNA from patients with mitochondrial encephalomyopathies.

OBJECTIVE: To study the relation between point mutations at nt3243 and nt8344 of muscle mitochondrial DNA from patients with mitochondrial encephalomyopathies and phenotypes. METHODS: DNA was extracted from muscle specimens from 5 patients with mitochondrial encephalomyopathies and and amplified by PCR method, using corresponding oligonucleotide primers. DNA fragments were digested with restriction enzymes Bgl I and Apa I, then the digested DNA fragments were analyzed with an electrophoresis method. RESULTS: The point mutation at nt3243 of mtDNA was found in 2 patients, one with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) and another with myoclonic epilepsy with ragged red fibers (MERRF). The point mutation at nt8344 was found in 2 patients with MERRF, including the one with point mutation at nt3243. CONCLUSION: The point mutation of DNA at nt3243 correlated with MELAS and nt8344 correlated with MERRF. In addition, the detection of point mutations at both nt3243 and nt8344 in a patient with MERRF shows the association of mutation with diversity in clinical manifestations of mitochondrial encephalomyopathies.

Adolescent↗
PubMed2001

[Experimental studies of the protective effects of basic fibroblast growth factor and Radix Salviae Miltiorrhizae on brain injury in rats caused by repeated exposures to +Gz].

Objective. To investigate the preventive and theralseutive (therapeutic) effects of basic fibroblast growth factor (bFGF) and Radix Salviae Miltiorrhizae (RSM) on brain injury caused by repeated +Gz exposures. Method. bFGF and RSM were injected intraperitoneally into SD rats before and after repeated +Gz exposures. The contents of excitatory amino acids (EAAs), nitric oxide (NO) and the number of cell apoptosis in the brain were measured, and were compared to those of the control group and normal saline (NS) group. Result. The contents of EAAs, NO and the number of cell apoptosis were significantly higher in repeated +Gz exposures group than those in control group. The values were markedly lower in bFGF and RSM group than those in repeated +Gz exposures group and NS group. Conclusion. bFGF and RSM showed distinct preventive and therapeutic effect on the brain injury induced by repeated +Gz exposures.

Animals↗
PubMed2001

[Mechanism of contour hedgerow's control for non-point pollution in the semiarid region in northwest Hebei Province].

Slope nutrient loss is an important type of non-point pollution. The mechanism of non-point pollution control by using plenty of natural observed data in Hilly Loess region in Northwest Hebei Province, as well as combating with the large-scale artificial simulation rainfall in the field slope was analyzed. The study results show that the critical slope length was 10-15 m on the condition of rainstorm, which led to the generation of rill and made the erosion amount went up obviously. The study show that the nutrient loss in sediment was the main type of non-point pollution, the contour hedgerow the process of non-point pollution by controlling the nutrient loss in sediment, then the study got the erosion control model of the contour hedgerow.

China↗
PubMed2001

[Chromosome t (8; 21) and t (15; 17) in a patient with acute myeloid leukemia].

OBJECTIVE: To report an acute myeloid leukemia (AML) patient with both chromosome t (8; 21) and t (15; 17). METHODS: Chromosome specimen was prepared by short-term culture of bone marrow cells, karyotype analyses by R-banding technique, and fusion genes by reverse transcriptase-polymerase chain reaction (RT-PCR). RESULT: Karyotype analyses showed the appearance of 45, X, -X, t (8; 21), t (15; 17), and RT-PCR assay revealed AML1/ETO and PML-RARalpha fusion gene transcripts. CONCLUSION: AML with both t (8; 21) and t (15; 17) might be recognized as a a novel subtype of acute leukemias.

Bone Marrow Cells↗
PubMed2001

[Vowel selection effects on the parameters of acoustic analysis].

OBJECTIVE: To investigate if there is difference about the parameters of acoustic analysis with the different vowel |a|, |i|, |ae| and decide which vowels is best fitted to the acoustic analysis. METHOD: 40 normal and 130 pathologic voice patients accepted acoustic analysis. Each acoustic parameters such as jitter, shimmer, NNE, SDF0, SNR were compared with different vowels. RESULT: Jitter, shimmer, NNE with |i| were much lower than that with |a| and |ae| in normal cases and light hoarseness group. While the acoustic parameters with |i| were much higher than that with |a| and |ae| in moderate and heavy hoarseness group. CONCLUSION: |a| and |ae| were the preferred vowels for normal and light hoarseness group, while the |i| could supply some useful suggestion for the moderate and heavy hoarse patients.

Adolescent↗
PubMed2001

[The relationship between acoustic analysis and auditory assessment].

OBJECTIVE: To investigate the relationship between acoustic analysis and auditory assessment of hoarseness. METHOD: 24 normal and 154 cases of pathological voice were included in this research. They were divided into 4 groups with different hoarseness and were accepted acoustic analysis. The parameters were analyzed by SPSS statistical software. RESULT: There were significant difference on acoustical parameters among each group excluding no difference of the jitter between normal and light hoarseness. NNE and SNR were the major parameters in descriptive of hoarseness. There were good correlation between 5 parameters and hoarseness assessment. CONCLUSION: Acoustic analysis is a useful method in clinical application to assess hoarseness with objective and simple advantage.

Adolescent↗
PubMed2001

[Detection of enterotoxin genes in Bacillus thuringiensis by PCR].

The presence of hemolysin HblA (hblA), enterotoxin BceT (bceT) and enterotoxin S (entS) genes from 45 strains of B. thuringiensis, 4 strains of B. cereus and B. sphaericus have been detected respectively by multiple PCR. The results showed that 95.6% B. thuringiensis strains contain the B component of hblA gene, 91.1% and 93.3% of them contain bceT and entS genes sequences respectively. The enterotoxin productions in all strains have also been analysis using two commercial immunoassay kits(TECRA and RPLA) and it has proved that most of B. thuringiensis stains and the positive B. cereus strain can produce entero toxins during their growth. However, the two hblA sequence positive stains, DBT007 was negative when tested both by RPLA and Tecra, T24 001 was negative when assayed by Tecra and positive by RPLA. One hblA sequence negative strain Dmu39 was negative when tested by RPLA but positive by Tecra. No enterotoxin and enterotoxin gene could be detected in B. thuringiensis DBT248 and the B. sphaericus strains. The results suggest that the potential risk of using B. thuringiensis, as biopesticide needs to be further evaluated.

Bacillus↗
PubMed2001

[Detection mucin gene in cervical lymph nodes in supraglottic cancer by reverse transcription polymerase chain reaction].

OBJECTIVE: To investigate the efficacy of discovery of cervical lymph nodes micrometastasis of supraglottic carcinomas by detection of mucin (MUC1) gene. METHODS: Twenty-five supraglottic carcinoma patients with clinically negative lymph nodes were performed neck dissection. MUC1 gene mRNA in these resected lymph nodes was detected by reverse transcription polymerase chain reaction (RT-PCR) and histopathological examination to find the potential micrometastasis. RESULTS: Of all 93 cervical lymph nodes, micrometastasis were found in 23 nodes of 6 case by histopathological examination and RT-PCR. Four of 19 cases with negative lymph nodes pathologically showed MUC1 gene expression and were identified to have metastasis by clinical recurrence and serial-sectioning. Therefore, the rate of detection of micrometastasis by this way was 16% (4/25), higher than that of regular pathologic methods. CONCLUSION: Detection of lymph nodes micrometastasis with RT-PCR method was more sensitive than that of regular pathologic methods. It is a valuable method to detect early lymph nodes metastasis.

Aged↗
PubMed2000

Interleukin-12 and Flt3 ligand differentially promote dendropoiesis in vivo.

Interleukin-12 (IL-12) and Flt3 ligand (FL) regulate hematopoiesis by stimulating proliferation, differentiation and migration of progenitor and/or stem cells. In this study, we evaluated the in vivo effect of IL-12 alone or in combination with FL on dendritic cell (DC) generation and accumulation in murine spleen, lymph node, thymus, liver, and tumor tissues. Both cytokines induced accumulation of functional DC in lymphoid and non-lymphoid tissues. IL-12 promoted predominantly myeloid dendropoiesis, while FL induced both myeloid and lymphoid dendropoiesis. Combination treatment resulted in a dramatic increase in CD86+, and particularly, NLDC-145+ cells within the liver, which was largely due to cell proliferation. Combination therapy also revealed the ability of FL to protect bone marrow cell populations from IL-12-induced depletion in vivo. In vitro, we found a significant FL-induced up-regulation of IL-12 production by DC at both mRNA and protein levels. Thus, our study suggests that (i) the antitumor activity of IL-12 may, at least in part, be mediated by the stimulation of dendropoiesis and (ii) IL-12 might contribute to the antitumor activity of FL. Furthermore, induction of DC generation in vivo by a combination of IL-12 and FL might become a new approach for immunotherapy of cancer.

Animals↗
PubMed2000

Double labeling immunoelectron microscopic study on the synaptic connections between glutamic acid neurons and GABA neurons in the hippocampus of rats.

In order to explore the roles of different neurotransmitters in epileptic pathogenesis, the synaptic connections between glutamic acid (Glu) neurons and GABA neurons in normal rat hippocampus were studied by pre-embedding double labeling immunoelectron microscopy. The GABA immunoreaction was first demonstrated by chromogen DAB, then the Glu immunoreaction was demonstrated by molybdic acid-TMB method. After being stabilized by DAB-cobalt chloride, the sections were processed for electron microscopic embedding. Under electron microscope, there were many Glu immunoreaction-positive neurons in the pyramidal layer of hippocampal CA1 area and some GABA immunoreaction-positive neurons with pyramidal or polygonal perikarya in the pyramidal, polymorphic and radiant layer of CA1 area. There were also symmetric dendro-axonic synapses formed by GABA-positive dendrites and Glu-positive axons in the polymorphic layer and symmetric axo-dendrites synapses formed by GABA-positive axons and Glu-positive dendritic in the radiant layer. In addition, there were symmetric autoregulatory axo-dendritic synapses between Glu-positive axons and dendrites and autoregulatory axo-axonic synapses (both symmetric and asymmetric) between GABA-positive axons. Above mentioned results, for the first time, showed that there were complex synaptic regulatory relationships between excitatory Glu neurons and inhibitory GABA neurons in the hippocampal CA1 area, thereby, providing ultrastructural evidence for different neurotransmitters participating in epileptic pathogenesis.

Animals↗
PubMed2000

Cytokine-mediated protection of human dendritic cells from prostate cancer-induced apoptosis is regulated by the Bcl-2 family of proteins.

Prostate cancer is the most common cancer in men in the United States, and second in cancer-induced mortality. It is likely that tumour-induced immunosuppression is one of the reasons for low treatment efficacy in patients with advanced prostate cancer. It has been recently demonstrated that prostate cancer tissue is almost devoid of dendritic cells (DC), the major antigen-presenting cells responsible for the induction of specific antitumour immune responses. In this study, we have tested the hypothesis that prostate cancer induces progressive suppression of the DC system. We found that co-incubation of human DC with three prostate cancer cell lines led to the high levels of premature apoptosis of DC, which were significantly higher than in DC cultures co-incubated with normal prostate cells or blood leucocytes. Stimulation of DC for 24 hours with CD40 ligand (CD154), IL-12 or IL-15 prior to their co-incubation with prostate cancer cells resulted in a significant increase in DC survival in the tumour microenvironment. Furthermore, activation of DC with these cytokines was also accompanied by increased expression of the anti-apoptotic protein Bcl-x(L) in DC, suggesting a possible mechanism involved in DC protection from apoptotic death. In summary, our data demonstrate that prostate cancer induces active elimination of DC in the tumour microenvironment. Stimulation of DC by CD154, IL-12 or IL-15 leads to an increased expression of the anti-apoptotic protein Bcl-x(L) and increased resistance of DC to prostate cancer-induced apoptosis. These results suggest a new mechanism of tumour escape from immune recognition and demonstrate the cytokine-based approaches which might significantly increase the efficacy of DC-based therapies for cancer.

Animals↗
PubMed2000

Tamoxifen-induced transient multifocal hepatic fatty infiltration.

Tamoxifen is one of the most commonly used anticancer medications. Hepatic damage secondary to tamoxifen treatment is rare. Tamoxifen-induced multifocal hepatic fatty infiltration has not been reported previously. This report describes one case of steatohepatitis caused by tamoxifen in an elderly woman with a history of breast cancer. The patient had multifocal hepatic fatty infiltration secondary to tamoxifen therapy. After tamoxifen was discontinued, the features of multifocal hepatic fatty infiltration on CT improved dramatically, and hepatic transaminases normalized.

Aged↗
PubMed2000

Synthesis and degradation of a tri-component copolymer derived from glycolide, L-lactide, and epsilon-caprolactone.

A series of tri-component copolymers was synthesized by ring opening copolymerization of cyclic lactones, i.e. glycolide, L-lactide, and caprolactone, using stannous octoate as a catalyst. Various techniques, including FT-IR, 1H NMR, DSC, X-ray diffraction, tensile strength, and contact angle measurements, were used to elucidate structural characteristics, thermal behavior, mechanical properties, and hydrophilicity of the resulting copolymers. Data showed that the properties of these copolymers could be modulated by adjusting the composition of the copolymers. The DSC and X-ray analysis demonstrated amorphous structures for most of the PGLC copolyesters. The degradation behavior of these PGLC copolymers had been studied in vitro, i.e. in 0.10 M pH 7.4 phosphate buffer solution (PBS). The degradation was monitored by intrinsic viscosity and weight loss measurements. SEM and GPC were also used to monitor the morphology and molecular weight change during degradation. The PGLC copolymers were shown to have variable degradation rates, and most of them could disappear within a few months due to their amorphous structure and low glass transition temperature.

Biocompatible Materials↗
PubMed2000

[Utilization of municipal sludge in agriculture and sustainable development].

Based on the ideas of sustainable development, this paper analyzed the features and disposal situations of municipal sludge and its influence on agricultural and urban development. It is suggested that the land application of municipal sludge is significant and urgent for urban and agricultural sustainable development. Land application of sludge will also be basic outlet for sludge disposal in the future. The key of land application of sludge lies in controlling the content of toxic pollutants in sludge and utilizing sludge scientifically.

Agriculture↗
PubMed2000

[Effect of plumular axis-cutted cotton on growth and development of cotton bollworm].

The method of plumular axis cutting was used to induce the resistance of cotton plants to cotton bollworms(Heliothis armigera). The bollworm was cultured in the laboratory, and the effect of induced cotton on the duration of larval development and weights of larvae and pupae was studied. In the treatments of infection and control, the lengths of larval period were delayed by 3 days and 0.5 days, the weights of larvae were decreased by 19.60% and 11.45%, and the pupae weights were decreased by 10.81% and 6.54%, respectively. After the 8 days old larvae were reared with induced cotton leaves for 3 days, the infected and uninfected cutted plants resulted in a decrease of the relative growth rates of larvae by 22.9% and 17.2% respectively, and in a decrease of the relative feeding rates by 26.1% and 21.4% respectively. It is suggested that plumular axis cutting could induce the resistance of cotton plants to bollworm, and influence the growth and development speed of bollworms through retarding their feeding and digestion. Combining with the treatment of Pseudomona gladioli D-2251 strain could obviously increase the insect-resistance of cotton plants.

Animals↗
PubMed2000

Lymphangiogenesis in tumor tissues and 5'-Nase, Flt-4, Flk-1 expressions.

OBJECTIVE: To investigate lymphangiogenesis in tumor tissues and 5'-Nase, Flt-4, Flk-1 expressions. METHODS: 5'-Nase and Aplase expressions and the morphology of lymphatics in gastric carcinoma tissues were observed with enzyme histochemistry. Flt-4 and Flk-1 expression in gastric carcinoma and sarcoma tissues was studied by immunohistochemistry. CNE-2z cells were implanted into the subdermal layer of nude mice and hyaluronic acid was injected at the same sites. After 4 or 5 weeks, nasopharyngeal carcinoma (NPC) xenograft tissues were cut for immunohistochemistry and enzyme histochemistry, and lymphangiogenesis, 5'-Nase, Alpase, Flt-4 and Flk-1 expression in NPC tissues was studied. Hyaluronic acid contents in sera of the patients with NPC and mice with NPC xenografts were measured by radioimmunoassay. RESULTS: There were a lot of lymphatics and solid strip-like tissues in gastric carcinoma and NPC xenograft treated with hyaluronic acid. The total number of lymphatics (26.9 +/- 14.2/HP) increased significantly in gastric carcinoma tissues. Flt-4 and Flk-1 positive expression was found in gastric carcinoma, sarcoma tissues and NPC xenograft. Most of the vessels with positive Flt-4 were lymphatics. Flk-1 expression was only found in the walls of blood vessels. Hyaluronic acid content (363.52 +/- 98.15 ng/ml) in sera of patients with NPC was higher than that of the patients with chronic nasopharyngeal inflammation (306.29 +/- 27.15 ng/ml), with a significant difference (P = 0.039). The hyaluronic acid content in sera of nude mice with NPC (2120.59 +/- 490.22 ng/ml) was markedly higher than that in normal mice (1588.99 +/- 502.12 ng/ml), with a significant difference between them (P = 0.007). CONCLUSION: There are a lot of lymph capillaries with positive 5'-Nase in gastric carcinoma and NPC xenograft treated with hyaluronic acid. Flt-4 positive expression is shown in gastric carcinoma, sarcoma tissues and NPC xenografts. The results suggest there is lymphangiogenesis in these malignant tumor tissues. Hyaluronic acid contents in sera of patients with NPC and nude mice with NPC increase, which may promote the formation of lymphatics.

5'-Nucleotidase↗
PubMed2000

Association of coagulation factor VII with the risk of myocardial infarction in the Chinese.

OBJECTIVE: To elucidate the association of plasma factor VII coagulant activity (FVIIc) with the risk of myocardial infarction (MI) and to assess the influence of factor VII gene MspI polymorphism and lipid metabolism on FVIIc in the Chinese. METHODS: A total of 137 patients with angiographically confirmed MI and 125 healthy individuals were evaluated retrospectively. Plasma FVIIc was measured by one-stage prothrombin time, and FVII genotype was determined after MspI digestion of polymerase chain reaction-amplified genomic DNA. Serum lipid levels were assessed by routine methods. RESULTS: MI patients had significantly higher levels of FVIIc (119.5% +/- 22.7% vs 99.9% +/- 21.8%, P < 0.01) and total serum cholesterol (5.80 +/- 1.06 mmol/L vs 5.53 +/- 1.08 mmol/L, P < 0.05) than controls, but only FVIIc independently correlated with the risk of MI (OR = 1.04, P < 0.01). There were no significant differences in FVII genotype or allele frequency between patients and controls (P > 0.05). Subjects with the Gln353 allele were associated with significantly lower FVIIc levels than Arg353 homozygotes (99.7% +/- 19.3% vs 111.4% +/- 24.6%, P < 0.05). Serum triglyceride was positively correlated with plasma FVIIc in both control (r = 0.25, P < 0.01) and case (r = 0.87, P < 0.01) groups, but this correlation was restricted to Arg/Arg genotype (r = 0.68, P < 0.01). A significant correlation of total serum cholesterol with FVIIc only appeared in Arg/Arg homozygotes (r = 0.17, P < 0.01). CONCLUSIONS: Our findings support the role of plasma FVIIc as a risk factor for MI in Chinese. Plasma triglyceride and FVII gene MspI polymorphism are two independent determinants of FVIIc. Assay of this polymorphism will be helpful in determining who will benefit most from lipid-lowing therapy.

Adolescent↗