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Biomedical subjects

Q Gao

Publications and source records attributed to Q Gao.

At least 91 records · Page 5Linked to original sources
PubMed2000

[Treatment of hemangioma in oral and maxillofacial region with pingyangmycin injection].

OBJECTIVE: To investigate the indication and result in hemangioma in oral and maxillofacial region with Pingyangmycin injection. METHODS: 1282 patients (554 males and 728 females) with hemangioma in oral and maxillofacial region have been treated in our hospital during the 10-year period from May 1990 to March 1999. The patients range between 0.5-84 years old. Lip, cheek and tongue were usually involved. 1211 patients were treated with injection of Pingyangmycin(about 0.89 mg/ml) and dexamethasone (about 0.55 mg/ml), 1 time/1-2 weeks. RESULTS: The curative rates of cavernous hemangioma and strawberry hemangioma were 93.87% and 84.90%, but that of plexiform hemangioma was 22.22% and those of portwine stain and central hemangioma of the jaws were 0%, respectively. Serious complications associated with Pingyangmycin injection, such as pulmonary fibrosis were not seen. CONCLUSION: Injection of Pingyangmycin is selective primary method for cavernous and strawberry hemangioma treatment.

Adolescent↗
PubMed2000

[Effect of Cordyceps sinensis on the Th1/Th2 cytokines in patients with Condyloma Acuminatum].

OBJECTIVE: To investigate the effect of cordyceps sinensis (CS) on the Th1/Th 2 cytokines and recurrence in patients with Condyloma Acuminatum (CA). METHOD: Double-antibody sandwich ELISA was used to study the serum level of IL-2 and IL-10 in 34 patients treated with CS(CS group) and 29 patients in control group. The recurrence rate of CA was observed. RESULT: After treated with CS, the serum levels of IL-2 and IL-10 significantly increased and decreased respectively (P < 0.05 or 0.01). No significant change occurred in control group. The recurrence times of CA in patients of CS group after electrocauterization were significantly lower than control group (P < 0.05). CONCLUSION: CS might recover the balance of Th1/Th2 cytokines and enhance Th 1 immune response in patients with CA, and reduced the recurrence of CA.

Adjuvants, Immunologic↗
PubMed1999

CD4+CD25+ cells regulate CD8 cell anergy in neonatal tolerant mice.

BACKGROUND: Injection of neonatal BALB/c mice with semi-allogeneic splenocytes leads to antigen-specific tolerance lasting into adulthood. Tolerant mice accept A/J skin grafts and fail to generate CD8 cytotoxic T lymphocyte (CTL) activity against A/J targets. Anergic CD8 T cells are present in tolerant mice, and CD4 regulatory cells function to maintain CD8 cell anergy. METHODS: Neonatal BALB/c mice were injected with 108 live CAF, splenocytes, and mice were deemed tolerant by accepting A/J grafts over 40 days. CD8 cell proliferation was measured by in vitro incorporation of bromodeoxyuridine coupled with fluorescence-activated cell sorter analysis. Alloantigen-specific cytotoxicity was tested using 51Cr release assays of A/J or third-party targets. RESULTS: We demonstrate that A/J-specific anergic CD8 cells are present in neonatal primed mice that develop tolerance but not in neonatal primed mice that reject A/J skin grafts. Anergic CD8 cells show decreased proliferation and no CTL activity against A/J targets. Addition of interleukin-2 (IL-2) to unfractionated cultures fails to restore CTL activity against A/J targets. However, addition of IL-2 to CD4-depleted cultures restores A/J-specific CD8 CTL activity. Removal of CD4+/CD25+ cells, but not CD4+/CD25- cells, also restores CD8 CTL activity against A/J in the presence, but not the absence, of IL-2. Moreover, when added back into cultures, purified CD4+/CD25+ cells from tolerant mice inhibit the generation of CD8 CTL against A/J targets. CONCLUSION: These data indicate that CD8 anergy is associated with the state of tolerance, and that CD4+CD25+ cells from tolerant mice function to maintain A/J-specific CD8 cell anergy in vitro.

Animals↗
PubMed1999

1alpha,25-dihydroxyvitamin D(3)-26,23-lactone analogs antagonize differentiation of human leukemia cells (HL-60 cells) but not of human acute promyelocytic leukemia cells (NB4 cells).

We examined the effects of two novel 1alpha,25-dihydroxyvitamin D(3)-26,23-lactone (1alpha,25-(OH)(2)D(3)-26,23-lactone) analogs on 1alpha,25(OH)(2)D(3)-induced differentiation of human leukemia HL-60 cells thought to be mediated by the genomic action of 1alpha, 25-dihydroxyvitamin D(3) (1alpha,25-(OH)(2)D(3)) and of acute promyelocytic leukemia NB4 cells thought to be mediated by non-genomic actions of 1alpha,25-(OH)(2)D(3). We found that the 1alpha,25-(OH)(2)D(3)-26,23-lactone analogs, (23S)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9647) and (23R)-25-dehydro-1alpha-hydroxyvitamin D(3)-26,23-lactone (TEI-9648), inhibited differentiation of HL-60 cells induced by 1alpha,25-(OH)(2)D(3). However, 1beta-hydroxyl diastereomers of these analogs, i.e. (23S)-25-dehydro-1beta-hydroxyvitamin D(3)-26, 23-lactone (1beta-TEI-9647) and (23R)-25-dehydro-1beta-hydroxyvitamin D(3)-26,23-lactone (1beta-TEI-9648), did not inhibit differentiation of HL-60 cells caused by 1alpha,25-(OH)(2)D(3). A separate study showed that the nuclear vitamin D receptor (VDR) binding affinities of the 1-hydroxyl diastereomers were about 200 and 90 times weaker than that of 1alpha-hydroxyl diastereomers, respectively. Moreover, none of these lactone analogs inhibited NB4 cell differentiation induced by 1alpha,25-(OH)(2)D(3). In contrast, 1beta,25-dihydroxyvitamin D(3) (1beta,25-(OH)(2)D(3)) and 1beta,24R-dihydroxyvitamin D(3) (1beta,24R-(OH)(2)D(3)) inhibited NB4 cell differentiation but not HL-60 cell differentiation. Collectively, the results suggested that 1-hydroxyl lactone analogs, i.e. TEI-9647 and TEI-9648, are antagonists of 1alpha,25-(OH)(2)D(3), specifically for the nuclear VDR-mediated genomic actions, but not for non-genomic actions.

Calcitriol↗
PubMed1999

Identification of candidate Drosophila olfactory receptors from genomic DNA sequence.

We have taken advantage of the availability of a large amount of Drosophila genomic DNA sequence in the Berkeley Drosophila Genome Project database ( approximately 1/5 of the genome) to identify a family of novel seven transmembrane domain encoding genes that are putative Drosophila olfactory receptors. Members of the family are expressed in distinct subsets of olfactory neurons, and certain family members are restricted to distinct portions of the olfactory system. This pattern of expression has interesting similarities to and differences from the expression patterns observed for olfactory receptors in vertebrates. The Drosophila olfactory system is simpler than mammalian systems, yet it is complex enough to present a fascinating system in which to study neural information processing. Moreover, the powerful genetic manipulations available in Drosophila, when combined with electrophysiological and behavioral analyses, make this an attractive model system in which to study olfactory discrimination.

Amino Acid Sequence↗
PubMed1999

Antagonistic action of novel 1alpha,25-dihydroxyvitamin D3-26, 23-lactone analogs on differentiation of human leukemia cells (HL-60) induced by 1alpha,25-dihydroxyvitamin D3.

We examined the effects of two novel 1alpha,25-dihydroxyvitamin D3-26,23-lactone (1alpha,25-lactone) analogues on human promyelocytic leukemia cell (HL-60) differentiation using the evaluation system of the vitamin D nuclear receptor (VDR)/vitamin D-responsive element (DRE)-mediated genomic action stimulated by 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3) and its analogues. We found that the 1alpha,25-lactone analogues (23S)-25-dehydro-1alpha-hydroxyvitamin-D3-26,23-lactone (TEI-9647), and (23R)-25-dehydro-1alpha-hydroxyvitamin-D3-26,23-lactone (TEI-9648) bound much more strongly to the VDR than the natural (23S, 25R)-1alpha,25(OH)2D3-26,23-lactone, but did not induce cell differentiation even at high concentrations (10(-6) M). Intriguingly, the differentiation of HL-60 cells induced by 1alpha,25(OH)2D3 was inhibited by either TEI-9647 or TEI-9648 but not by the natural lactone. In contrast, retinoic acid or 12-O-tetradecanoylphorbol-13-acetate-induced HL-60 cell differentiation was not blocked by TEI-9647 or TEI-9648. In separate studies, TEI-9647 (10(-7) M) was found to be an effective antagonist of both 1alpha,25(OH)2D3 (10(-8) M) mediated induction of p21(WAF1, CIP1) in HL-60 cells and activation of the luciferase reporter assay in COS-7 cells transfected with cDNA containing the DRE of the rat 25(OH)D3-24-hydroxylase gene and cDNA of the human VDR. Collectively the results strongly suggest that our novel 1alpha,25-lactone analogues, TEI-9647 and TEI-9648, are specific antagonists of 1alpha, 25(OH)2D3 action, specifically VDR/DRE-mediated genomic action. As such, they represent the first examples of antagonists, which act on the nuclear VDR.

Animals↗
PubMed1999

Simultaneous genetic typing from multiple short tandem repeat loci using a 96-capillary array electrophoresis system.

Short tandem repeat (STR) markers are highly polymorphic and widely used in human identification and genetic mapping. We demonstrate fast and reliable genotyping based on the four STR loci vWF, THO1, TPOX, CSF1PO by multiple-capillary array electrophoresis. Extracted human genomic DNA was amplified by polymerase chain reaction (PCR). The PCR products were mixed with pooled allelic ladder as an absolute standard and coinjected from a 96-vial tray. Separations were performed in polyvinylpyrrolidone (PVP) sieving matrix with a one-hour turnaround time, with no degradation over 27 runs. Simultaneous one-color laser-induced fluorescence detection was achieved by using a charge-coupled device (CCD) camera. The allele peaks for the unknown sample were identified by comparing the normalized peak intensities of the mixtures to those of the pooled ladder by using a straightforward algorithm. An extremely high level of confidence in matching the bands was indicated with negligible crosstalk (< 0.89%) between adjacent capillaries. This scheme is applicable for STR genotyping with high resolution, high speed and high throughput.

Algorithms↗
PubMed1999

Firefly luciferase as a reporter to study gene expression in Streptococcus mutans.

The utility of firefly luciferase as a reporter was tested in Streptococcus mutans. Under control of an endogenous promoter, the luciferase coding sequence was strongly expressed, while a promoterless version was indistinguishable from the background. Luciferase activity was easily extracted and the assay rapid and reproducible. In addition, the half-life of luciferase activity was found to be comparable to those of other frequently used reporters. Thus, firefly luciferase can readily be used as a reporter in S. mutans, a useful alternative to methods requiring radioactive isotopes.

Animals↗
PubMed1999

Application of transcranial Doppler in subarachnoid hemorrhage.

Transcranial Doppler (TCD) was dynamically performed on 25 patients with subarachnoid hemorrhage (SAH) before and after treatment. In the first 4 days of clinical course, 3 cases demonstrated elevated intracranial pressure (ICP), 6 cases showed stenosis of blood vessels, and 16 cases gave normal findings. At 7-14 days of clinical course, 20 cases showed vascular spasm or narrowing, 4 cases imparted normal findings and 1 patient died of elevated ICP. After the third TCD performed on the 20th day of the clinical course, 5 cases showed mean blood flow velocities (Vm) below normal values, indicating poor cerebral perfusion, 9 cases still had Vm above normal levels, 10 cases yielded completely normal findings. In conclusion, TCD conducted at different phases of SAH can not only demonstrate the functional and pathological status of cerebral blood vessels following SAH, but also reflect the outcome of clinical features. It is very helpful in the evaluation of the causes and the prognosis of SAH.

Adult↗
PubMed1999

Treatment field shape verification using elliptic Fourier transform.

An automated field shape correlation technique based on elliptic Fourier transform (EFT) is developed to verify the radiation treatment field in digital portal images. In this method, the edge of the treatment field is initially extracted from the portal image and is then approximated by a polygon. The polygon is further represented with elliptic Fourier coefficients. The invariants to shift, rotation, and scale are computed from the elliptic Fourier coefficients to characterize the genuine shape feature and are used to match the reference treatment field. Invariants calculated from both test and reference field shapes are compared to determine the similarity between two treatment fields. The proposed procedure uses the first approved field shape as the reference for automated comparison with subsequent portal images. This technique not only verifies the shape of each portal field but also provides information about relative shift, rotation, and scale. A set of generic shapes is simulated to test the robustness of the algorithm and to determine the parameters used in the decision procedure. Experimental results on the simulated shapes show that this method can detect shape distortions of 2% in area and the standard deviations are 0 for shifting, 0.24 degrees for rotation, and 0.0031 for scaling. Preliminary tests on clinical portal images indicated that this technique is potentially useful for automated real-time portal verification.

Algorithms↗
PubMed1999

In vitro selection of integration host factor binding sites.

Integration host factor (IHF) is a bacterial protein that binds and severely bends a specific DNA target. IHF binding sites are approximately 30 to 35 bp long and are apparently divided into two domains. While the 3' domain is conserved, the 5' domain is degenerate but is typically AT rich. As a result of physical constraints that IHF must impose on DNA in order to bind, it is believed that this 5' domain must possess structural characteristics conducive for both binding and bending with little regard for specific contacts between the protein and the DNA. We have examined the sequence requirements of the 5' binding domain of the IHF binding target. Using a SELEX procedure, we randomized and selected variants of a natural IHF site. We then analyzed these variants to determine how the 5' binding domain affects the structure, affinity, and function of an IHF-DNA complex in a native system. Despite finding individual sequences that varied over 100-fold in affinity for IHF, we found no apparent correlation between affinity and function.

Bacterial Proteins↗
PubMed1999

Multiple functions of human papillomavirus type 16 E6 contribute to the immortalization of mammary epithelial cells.

The E6 proteins from cervical cancer-associated human papillomavirus (HPV) types such as HPV type 16 (HPV-16) induce proteolysis of the p53 tumor suppressor protein through interaction with E6-AP. We have previously shown that human mammary epithelial cells (MECs) immortalized by HPV-16 E6 display low levels of p53. HPV-16 E6 as well as other cancer-related papillomavirus E6 proteins also binds the cellular protein E6BP (ERC-55). To explore the potential functional significance of these interactions, we created and analyzed a series of E6 mutants for their ability to interact with E6-AP, p53, and E6BP in vitro. While there was a similar pattern of binding among these E6 targets, a subset of mutants differentiated E6-AP binding, p53 binding, and p53 degradation activities. These results demonstrated that E6 binding to E6-AP is not sufficient for binding to p53 and that E6 binding to p53 is not sufficient for inducing p53 degradation. The in vivo activity of these HPV-16 E6 mutants was tested in MECs. In agreement with the in vitro results, most of these p53 degradation-defective E6 mutants were unable to reduce the p53 level in early-passage MECs. Interestingly, several mutants that showed severely reduced ability for interacting with E6-AP, p53, and E6BP in vitro efficiently immortalized MECs. These immortalized cells exhibited low p53 levels at late passage. Furthermore, mutants defective for p53 degradation but able to immortalize MECs were also identified, and the immortal cells retained normal levels of p53 protein. These results imply that multiple functions of HPV-16 E6 contribute to MEC immortalization.

Animals↗
PubMed1999

The E6 oncoproteins of high-risk papillomaviruses bind to a novel putative GAP protein, E6TP1, and target it for degradation.

The high-risk human papillomaviruses (HPVs) are associated with carcinomas of the cervix and other genital tumors. Previous studies have identified two viral oncoproteins, E6 and E7, which are expressed in the majority of HPV-associated carcinomas. The ability of high-risk HPV E6 protein to immortalize human mammary epithelial cells (MECs) has provided a single-gene model to study the mechanisms of E6-induced oncogenic transformation. In this system, the E6 protein targets the p53 tumor suppressor protein for degradation, and mutational analyses have shown that E6-induced degradation of p53 protein is required for MEC immortalization. However, the inability of most dominant-negative p53 mutants to induce efficient immortalization of MECs suggests the existence of additional targets of the HPV E6 oncoprotein. Using the yeast two-hybrid system, we have isolated a novel E6-binding protein. This polypeptide, designated E6TP1 (E6-targeted protein 1), exhibits high homology to GTPase-activating proteins for Rap, including SPA-1, tuberin, and Rap1GAP. The mRNA for E6TP1 is widely expressed in tissues and in vitro-cultured cell lines. The gene for E6TP1 localizes to chromosome 14q23.2-14q24.3 within a locus that has been shown to undergo loss of heterozygosity in malignant meningiomas. Importantly, E6TP1 is targeted for degradation by the high-risk but not the low-risk HPV E6 proteins both in vitro and in vivo. Furthermore, the immortalization-competent but not the immortalization-incompetent HPV16 E6 mutants target the E6TP1 protein for degradation. Our results identify a novel target for the E6 oncoprotein and provide a potential link between HPV E6 oncogenesis and alteration of a small G protein signaling pathway.

Amino Acid Sequence↗
PubMed1999

[Systemic inflammatory response syndrome in critical patients - an analysis of 1,292 cases].

OBJECTIVE: To study the significance of the occurrence and the development of systemic inflammatory response syndrome (SIRS) in critical patients. METHODS: The clinical data of 1292 patients accepted by our hospital in ten months from October 1995 to July 1996 were analyzed. The patients met at least two of the criteria for SIRS such as fever, hypothermia, tachycardia, tachypnea or abnormal white blood cell count. RESULTS: 1292 (67.7%) of the 1909 patients investigated met two or more of the criteria for SIRS. In the 1292 cases, those who met two, three or four of the criteria were respectively 467 (36.1%), 526 (40.7%) and 299 (23.1%). 149 patients (11.5%) in the 1292 cases died of multiple organ dysfunction syndrome (MODS). In which 33 (7.1%), 57 (10.8%) and 59 (19.7%) respectively in patients with two, three and four of the criteria for SIRS. The proportion of patients suffering from acute respiratory distress syndrome, metabolic function dysfunction, disseminated intravascular coagulation and acute renal failure increased with the increase in the number of SIRS criteria that the patients met and with the increase in the proportion of patients progressing from SIRS to septic shock. The mortality rate of the patients also gradually increased while the patients with SIRS were developing sepsis, severe sepsis and septic shock, but there was no statistical significance (P > 0.05). CONCLUSION: It is suggested that bacterial infection, severe trauma and acute pancreatitis might cause SIRS and compensatory anti-inflammatory response syndrome might play an important role in the maintenance of internal environment of the body. A comprehensive understanding of SIRS might be of help to the management of critical diseases.

Adolescent↗
PubMed1999

[Evaluation of atrial natriuretic peptide in differentiating benign and malignant pleural effusion].

OBJECTIVE: To discuss the value of atrial natriuretic peptide (ANP) in differentiating benign and malignant pleural effusion. METHODS: Direct radioimmunoassay was used to detect ANP of pleural effusion and serum in 30 tuberculous and 26 cancerous pleural effusion patients. RESULTS: The ANP in tuberculous and cancerous pleural effusion were (75 +/- 9) ng/L, (157 +/- 45) ng/L respectively, and significant difference was found (P < 0.001). The ANP of tuberculous pleural effusion was apparently lower [(75 +/- 9) ng/L] than serum [(170 +/- 37) ng/L], and significant difference was also found (P < 0.001). The ratio of ANP of pleural effusion to that of serum were 0.47 +/- 0.17, 0.99 +/- 0.46 respectively in tuberculous and cancerous pleural effusion patients. The sensitivity of ANP was 81% and specificity 100% in diagnosing malignant pleural effusion. CONCLUSIONS: Detecting ANP of pleural effusion is one of important methods for differentiating benign and malignant pleural effusion.

Adolescent↗
PubMed1999

[Expression of membrane-type I matrix metalloproteinase and its correlation with gelatinase A activation in cancer cell lines].

OBJECTIVE: To study the expression of membrane-type I matrix metalloproteinase (MT1-MMP) and its correlation with gelatinase A (MMP2) activation. METHODS: Reverse transcription PCR, northern blots and western blots were employed to detect the expression levels of MT1-MMP mRNA and MMP2 protein in 4 human melanoma cell lines, 2 human lung cancer cell lines and 2 human prostate cancer cell lines. RESULTS: All the cancer cell lines expressed MT1-MMP mRNA, and the MT1-MMP mRNA level in the 4 melanoma cell lines was significantly higher than that in the lung and prostate cancer cell lines. Activated MMP2 proteins were only detected in the melanoma cell lines, whereas PG, a lung cancer cell line, which secreted pro-MMP2 and expressed low level of MT1-MMP, could not produce activated MMP2. CONCLUSIONS: The level of MT1-MMP expression was highly associated with MMP2 activation.

Blotting, Northern↗
PubMed1999

[Diagnosis and treatment of central hemangioma of mandible].

OBJECTIVE: To investigate methods of diagnosis and treatment of hemangiomas of the mandible. METHODS: Nineteen cases of central hemangioma of the mandible treated in our department from 1971 to 1997 were studied retrospectively. Fourteen patients received surgical treatment in which ten patients had received complete curettage of the lesion and the other four had received part resection of the mandible. RESULTS: The most common signs and symptoms of this lesion were hypermobility of teeth and episodes of spontaneous hemorrhage from the surrounding gingival sulcus. Selective angiography was significant in the diagnosis of this lesion. Fourteen patients received surgical treatment and thirteen lesions were removed completely, except that one died of massive bleeding at the operation and DIC on the next day. CONCLUSION: Selective angiography is useful to diagnosis the central hemangioma of mandible, and the complete curettage of the hemangiomas in the body of mandible is the most appropriate operation for children. At the same time, ligature of the inferior alveolar artery can reduce the risk of bleeding during operation.

Adolescent↗