Biomedical subjects

Q Kong

Publications and source records attributed to Q Kong.

At least 37 records · Page 2Linked to original sources

PubMed2001

[Diagnosis and management of endoleak after endovascular repair of abdominal aortic aneurysm].

OBJECTIVE: To determine the diagnosis and management of endoleak after endovascular repair of abdominal aortic aneurysm (AAA). METHODS: We analysed retrospectively the data of 37 cases of infrarenal AAA treated by endovascular repair and investigated the reasons, managements, results and prognosis of endoleaks. RESULTS: Of 13 patients with endoleak at stent-graft deployment, 6 developed type I endoleak, 3 type II endoleak, 2 type III endoleak, 1 type IV endoleak, and 1 unknown reason. Type I and III endoleaks disappeared after management with additional techniques. The primary endoleak rate was 13.5%(5/37). Three sealed endoleak, 2 persistent endoleaks and 2 secondary endoleaks were found during follow up. The late endoleak rate was 10.8% (4/37). CONCLUSIONS: Endoleak is a chief complication after endovascular repair of infrarenal AAA. The influencing factors for endoleak include neck morphology, distance, angulation, calcification, stent-graft selection and side branching arteries. Additional procedure and follow up are very important. Techniques to find endoleak include CTA, Duplex and MRA after operation. Endoleak with enlarged aneurysm should be treated actively.

Aortic Aneurysm, Abdominal↗

PubMed2000

A threshold concept for cancer therapy.

Oxygen free radicals have been implicated in many disease processes, including aging and carcinogenesis, and have been associated with a variety of complications resulting from the treatment of cancer. As a result, the treatment of free radical-induced disease with antioxidants or free radical scavengers has become an important therapeutic modality. Ironically, these same oxygen free radicals also play a critical role in anti-cancer therapies. The use of antioxidants such as superoxide dismutase (SOD), in this setting, has been found to decrease the efficacy of anti-tumor therapies, which depend on free radical generation for their action. In addition, increased antioxidant activity can often be utilized by the tumor cell to favor increased growth. Therefore, the appropriate application of oxygen free radicals and antioxidants seems to be critically important in designing proper strategies for both prevention and treatment of malignant disorders. This review will summarize free radical and antioxidant regimens that have been employed to date, examine some of the problems associated with these regimens, introduce the 'threshold concept' explaining the dual effects of oxygen free radicals and antioxidants, and discuss a novel hypothesis regarding therapy that could potentially improve outcome in cancer patients.

Antioxidants↗

PubMed2000

Conditions for electron capture by an ultraintense stationary laser beam

We present in this paper a quantitative study of an effect, in which a low-energy free electron is captured and violently accelerated to GeV final kinetic energy by a stationary extra-high-intensity laser beam (Q0 identical witheE/m(e)omegac greater, similar100). The conditions under which this phenomenon can occur, such as the momentum range, incident angle of the incoming electron, the waist width of the laser beam, etc., have been investigated in detail.

Journal Article↗

PubMed2000

[The study on relation of human papillomavirus and P53 expression with bladder transitional cell carcinoma].

OBJECTIVE: To study the relationship between the bladder transitional cell carcinoma and the human papillomavirus (HPV) types 6, 11, 16, 18 and P53. METHODS: We used polymerase chain reaction (PCR) to test HPV type 6, 11, 16 and 18 infection from 75 cases of bladder cancer, and used immunohistochemistry method to detect P53 expression. RESULTS: The positive rates of HPV types 6, 11, 16 and 18 were 6.7%, 5.3%, 33.3% and 6.7%, respectively. The positive rate of low risk HPV type (6/11) was 9.3% (7/75), and that of high risk HPV types (16/18) was 34.7% (26/75). There were 8 cases with two or three HPV types mixed infection, accounting for 10.6%, HPV types 6,11,16,18 in tumor metastasis group were significantly higher than that in non-metastasis group. The positive rates of HPV 16, 18 types in G3 were significantly higher than that in G1 and G2. HPV type 16 was the main type in bladder cancer. Positive rate of P53 expression was 44%. CONCLUSIONS: These results implicated that the occurrence and development of bladder transitional cell carcinoma may be closely related to the high risk HPV type infection and P53 expression.

Adult↗

PubMed2000

[Distribution of interleukin-6 receptors (CD(126) and CD(w130)) on circulating lymphocytes in patients with lupus nephritis].

OBJECTIVE: To study the distribution of IL-6 receptors (CD(126) and CD(w130)) on lymphocytes in patients with lupus nephritis (LN). METHOD: The percentages of lymphocyte subsets were examined by direct two colour immunofluorescence on flow cytometry. RESULTS: (1) In active and inactive cases, the percentages of CD(+)(4) cells obviously decreased as compared with the normal controls (P < 0.01). Increased numbers of CD(+)(8) cells could be detected in LN patients (P < 0.05), especially in active cases (P < 0.01). Lymphocytes of active cases contained significantly greater percentage of CD(+)(23) cells than those of normal subjects (P < 0.05). On the contrary, the percentage of CD(+)(23) cells was statistically lower in the inactive cases than in normal subjects (P < 0.01). No significant difference in the percentages of CD(+)(126) and CD(+)(w130) cells was observed among the active, inactive and healthy groups (P > 0.05); (2) The proportion of CD(+)(4) CD(+)(126) and CD(+)(4) CD(+)(w130) cells in total lymphocytes was significantly lower in the active than in the inactive ones or normal subjects (P < 0.05; P < 0.01), whereas that of CD(+)(8) CD(+)(126) and CD(+)(8) CD(+)(w130) cells was not different among the active, inactive and normal subjects (P > 0.05). The proportion of CD(+)(23) CD(+)(126) cells and CD(+)(23) CD(+)(w130) cells augmented significantly in the active (P < 0.05), whereas it lessened in the inactive without statistical meaning as compared with the normal subjects (P > 0.05). (3) There was a positive correlation between the percentage of CD(+)(23) CD(+)(126) cells and that of CD(+)(23) CD(+)(w130) cells in total lymphocytes in the active group (r = 0.756, P < 0.05). However, no correlation between the percentage of CD(+)(23) CD(+)(126) cells and that of CD(+)(23) CD(+)(w130) cells in total lymphocytes was found in the inactive (r = 0.376, P > 0.05) or normal group (r = 0.256, P > 0.05); (4) The fraction of CD(+)(23) cells expressing CD(126) and CD(w130) was related to the SLE disease activity index (SLEDAI) and lymphopenia (P < 0.05, P < 0.005). But it was neither associated with the number of damaged organs and the degree of damage, not with that of ANA, anti-dsDNA antibody and complements (C(3) and C(4)) (P > 0.05). CONCLUSIONS: LN patients present not only B cell hyperactivity but also T cell abnormality. In active cases, there is abnormal distribution of IL-6 receptors on lymphocytes: reduced CD(126) and CD(w130) expression on CD(+)(4) cells and elevated CD(126) and CD(w130) expression on CD(+)(23) cells. Detecting the proportion of CD(+)(23) CD(+)(126) cells or CD(+)(23) CD(+)(w130) cells in total lymphocytes may serve as one of activity indexes for LN patients.

Adolescent↗

PubMed2000

[Endoluminal stent-graft repair of aortic aneurysms].

OBJECTIVE: To study the clinical value of the treatment of aortic aneurysms with endovascular stent-graft prosthesis. METHODS: After a unilateral surgical arteriotomy, Talent, Vanguard and Chinese stent-graft were advanced through the femoral arteries and placed in the proper position of the aneurysm sac under X-ray fluoroscopic guidance. RESULTS: Four patients with descending aneurysm, 1 patient with abdominal aortic aneurysm (AAA) involving the renal artery, superior mesenteric artery and celiac artery, and 1 patient with right common iliac artery aneurysm received straight stent-grafts. Five patients with infrarenal AAA received bifurcated stent-grafts. CT and MRA were performed during a follow-up of 3 - 19 months. Aortic aneurysms were completely excluded from the circulation. Five patients prolonged fever was noted and 1 patient was found to have a leakage 3 months later, and hemiplegia in 1 after procedure. CONCLUSIONS: Endovascular treatment of aortic aneurysm is technically feasible and can effectively exclude aortic aneurysms from the circulation. Endoluminal repair may serve as an interventional strategy to treat aneurysm, especially in patients at high surgical risk, but long term effect needs further study.

Adult↗

PubMed2000

[Abdominal aortic aneurysm treated by endovascular stent-graft and conventional surgical repair: a comparison].

OBJECTIVE: To evaluate the feasibility of abdominal aortic aneurysm (AAA) treated by endovascular stent-graft. METHODS: The clinical data of 52 patients with AAA treated by endovascular stent-graft (n = 20) and conventional surgical repair (n = 32) were analysed retrospectively. Patients conditions, operative hours, blood loss, function recovery and complications were compared. RESULTS: No significant difference was observed in sex, age, other disease, anesthesia risk category, aneurysm type, aneurysm diameter, technical success rate, and mortality rate between the groups (P > 0.05). The patients who underwent intraluminal treatment had significant reductions in operative time, blood loss, intensive care unit and hospitalization. But there was a high complication rate in the endovascular stent-graft group. All complications were connected with the interventional technique; endo-leak was the chief complication after operation. CONCLUSIONS: Endovascular treatment has marked merits such as reduced trauma, short hospitalization stays, and early functional recovery. It is suitable for the patients who can't undergo open surgical repair. But the complications caused by this technique needs further study.

Aged↗

PubMed1999

Urinary N-acetyl-beta-D-glucosaminidase isoenzymes as biomarker of renal dysfunction caused by cadmium in a general population.

N-Acetyl-beta-D-glucosaminidase (NAG) and its isoenzymes in urine have been studied in a population group residing in a polluted area in China. The area studied was contaminated by industrial wastewater from a nearby smelter that discharged cadmium-polluted wastewater into a river used for the irrigation of rice fields. Cadmium concentrations in rice were 3.70, 0.51, and 0.07 mg/kg for the highly and moderately polluted areas and the control area, respectively. Cadmium concentrations in urine exceeded 5 microgram/liter in the majority of subjects in the most highly polluted area. There was a marked dose-dependent increase in NAG and NAG B content of urine related both to urinary cadmium and to the calculated cadmium uptake. It is concluded that urinary NAG and its isoenzymes could serve as a sensitive biomarker of renal dysfunction in cadmium-exposed populations. The mechanisms underlying the increase in NAG and its isoenzymes after cadmium exposure need to be studied further.

Acetylglucosamine↗

PubMed1999

Current perspectives in immunotherapy.

Since the declaration of the war on cancer in 1971, our ability to effectively treat cancer has been less successful than anticipated. Surgery and radiation therapy remain our most effective treatment modalities, with chemotherapy proving beneficial in only a limited number of tumor types. The reality of this poor response to conventional therapy has prompted a search for other potentially beneficial therapies. The idea of using the immune system to eradicate tumor is not new. Over 100 years ago, William Coley (in 1893) first reported on the ability to induce tumor regressions by nonspecific activation of the immune system in response to bacterial toxins. Despite this early beginning, efforts to reliably manipulate the immune system to promote tumor regression has been universally disappointing. With recent advances in our understanding of the immune system, and the identification and availability of numerous growth promoting and growth-suppression cytokines, the concept of immunotherapy being a useful therapeutic intervention for the treatment of cancer is becoming a reality. Immunology in general, and tumor immunology specifically, are fields foreign to the practicing tumor surgeon. As progress in these fields are made, it will become important for the surgical oncologist to have a better understanding of tumor immunology as it relates to therapy. This paper reviews our current understanding of the immune system as it relates to cancer immunotherapy (using primary intracranial glioma as the tumor model), and then relates this knowledge to recent work in the development of tumor-specific vaccines.

Cytokines↗

PubMed1999

Color Doppler energy and related quantitative analysis of gestational trophoblastic tumors.

OBJECTIVE: To assess the reliability of color Doppler energy (CDE) and a related quantitative analysis for detection and follow-up of uterine involvement in gestational trophoblastic tumor. METHOD: CDE was performed in 19 patients with trophoblastic tumor, in 25 women in early pregnancy and 25 non-pregnant women. The blood flow area ratio (BFAR) in CDE was used as an index representing uterine involvement. In nine of the 19 patients, BFAR was measured before, during and at termination of chemotherapy. RESULT: The BFAR (mean +/- S.D.) of uterine profiles in 19 patients (39.9 +/- 1.3%) was significantly higher than that in 25 pregnant women (24.6 +/- 10.1%, P = 0.002) and in 25 non-pregnant women (14.8 +/- 5.7%, P = 0.001). In the follow-up of nine patients, when beta-hCG was less than 3.1 ng/ml during the treatment, the BFAR (38.7 +/- 11.9%) decreased below that (44.2 +/- 14.6%) seen prior to treatment (P = 0.009) and was much lower at termination of treatment (27.5 +/- 12.3%, P = 0.048). CONCLUSION: These data support the use of CDE and the related quantitative analysis as a new method for detecting and follow-up of uterine involvement in patients with trophoblastic tumors.

Adult↗

PubMed1999

PMS2-deficiency diminishes hypermutation of a lambda1 transgene in young but not older mice.

The Pms2 gene is involved in DNA mismatch repair in mammalian cells, and has recently been shown to affect hypermutation of mammalian immunoglobulin genes. We have studied hypermutation of a lambda1 transgene in chronically stimulated Peyer's patch B cells of both young and old mice deficient in function of Pms2. In young (3-4 months) mice, somatic hypermutation is fourfold lower in PMS2-deficient mice than in control mice. This difference is statistically significant (P < 0.05). In contrast, in older mice (9 months of age), hypermutation levels are indistinguishable in the Pms2-/- and Pms2+/+ backgrounds. In the older mice, there was no clear difference in the fraction of clones carrying either any mutations or at least two mutations when PMS2-deficient mice were compared with their wild-type littermates. As genomic instability increases with age, this observation is difficult to reconcile with the hypothesis that highly mutated B cells cannot survive in Peyer's patches. Moreover, there were clear differences apparent in the mutation spectra of the Pms2-/- and Pms2+/+ mice. In the PMS2-deficient background, deletion and insertion mutations were found, and there was a significant decrease in the ratio of A mutations to T mutations in comparison with the Pms2+/+ controls. Our data support the hypothesis that PMS2 functions in somatic hypermutation, and are most consistent with the hypothesis that the role of PMS2 is direct rather than indirect.

Adenosine Triphosphatases↗

PubMed1999

Somatic hypermutation and the three R's: repair, replication and recombination.

Somatic hypermutation introduces single base changes into the rearranged variable (V) regions of antigen activated B cells at a rate of approximately 1 mutation per kilobase per generation. This is nearly a million-fold higher than the typical mutation rate in a mammalian somatic cell. Rampant mutation at this level could have a devastating effect, but somatic hypermutation is accurately targeted and tightly regulated. Here, we provide an overview of immunoglobulin gene somatic hypermutation; discuss mechanisms of mutation in model organisms that may be relevant to the hypermutation mechanism; and review recent advances toward understanding the possible role(s) of DNA repair, replication, and recombination in this fascinating process.

Animals↗

PubMed1999

High-intensity laser-induced electron acceleration in vacuum.

In this paper, an approximate pulsed-laser-beam solution of Maxwell's equation in vacuum is derived. Then with the numerical simulation method, electron acceleration induced by high-intensity [Q(0)=eE(0)/(m(e)omega c)=3] lasers is discussed in connection with the recent experiment of Malka et al. It is found that the maximum energy gain and the relationship between the final energy and the scattering angle can be well reproduced, but the polarization effect of electron-laser interactions is not very prominent. These results show that the ponderomotive potential model is still applicable, which means that the stimulated Compton scattering is the main fundamental mechanism responsible for the electron acceleration at this laser intensity.

Journal Article↗

PubMed1999

[Regulation of adherence to serum-coated hydroxyapatite by Streptococcus sanguis].

OBJECTIVE: To investigate the effects of pH and calcium iron on adhesion of Streptococcus sanguis to serum-coated hydroxyapatite. METHODS: The adhesion model in vitro established by Clark W. B. in 1977 was used to quantify adsorptive cells through [3H] thymidine labelling. RESULTS: The cpm values between different pH groups showed significant differences. Also, there were significant differences of cpm values between calcium groups and control group. CONCLUSION: Either pH or calcium iron has obvious effect on adherence of Stroptococcus sanguis to serum-coated hydroxyapatite. The findings suggest that regulating pH and concentration of calcium iron can help to change colonization on teeth surfaces by Streptococcus sanguis in periodontal circumstance.

Animals↗

PubMed1999

[Clinical significance and expression of Bcl-2 protein in patients with systemic lupus erythematosus].

OBJECTIVE: To investigate the pathogenesis and clinical evaluation for expression of Bcl-2 in lymphocytes and renal tissues of 31 patients with systemic lupus erythematosus (SLE). METHODS: Bcl-2 protein levels in T, B cells and renal tissues were examined by two-colour cytofluorography, and immunohistochemical staining (LSAB method) respectively. RESULTS: Compared with inactive SLE patients and normal controls, a proposition of T cells (including CD(3)(+), CD(4)(+) and CD(8)(+) subgroups) expressing Bcl-2 protein increased significantly in active SLE patients. However, Bcl-2 protein levels are not statistically different in CD(19)(+) B cells among all groups. Mean fluorescence intensity (MFI) levels of Bcl-2 protein on CD(3)(+) T cells was positively related to SLE disease activity index (SLEDAI) among the SLE patients, which wasn't related to ESR, complement (C(3), C(4)) and autoantibody (ANA, anti-dsDNA, anti-Sm) positivity. The population of Bcl-2 positive intraglomerular cells was correlated significantly with the grade of mesangial cell increase and the number of proliferating cell nuclear antigen (PCNA) positive glomerular cells, and 24-hour urinary protein. CONCLUSION: Overexpression of apoptosis-related Bcl-2 protein might play an important rule in the prolonged proliferation of mesangial cells and glomerular hypercellularity and in the active period of SLE patients, Bcl-2 expression levels of peripheral blood T lymphocytes might serve as an active index for SLE.

Adult↗

PubMed1999

[The study on cytomegalovirus infection associated with vascular complications in patients with essential hypertension].

OBJECTIVE: This paper studied HCMV infection inpatients with essential hypertension and the relationship of HCMV infection with vascular complications. METHODS: Indirect ELISA method was used to detect human cytomegalovirus (HCMV) specific antibodies in sera of 105 patients with essential hypertension. RESULTS: The results showed that the positive rates of active HCMV-IgM and IgA antibodies were 26.67% and 20.95%, respectively, higher than that of the control group (6.67%). The positive rate of HCMV active IgM antibody in III stage group was significantly higher than that of I + II stage groups (P < 0.01). Active HCMV infective rate was higher in patients with vascular complication. CONCLUSION: These results suggested that HCMV active infection may be associated with vascular complication.

Adult↗

PubMed1998

A lambda 3' enhancer drives active and untemplated somatic hypermutation of a lambda 1 transgene.

Somatic hypermutation is a highly regulated process that targets mutations to the rearranged Ig genes. Little is known about the cis-elements required for somatic hypermutation of the lambda light chain gene. We have studied somatic hypermutation of a rearranged lambda 1 transgene under the control of either a lambda 2-4 or kappa 3' enhancer. The mutations in the transgenes were analyzed by sequencing DNA amplified from hypermutating Peyer's patch B cells. The results indicate that the lambda 3' enhancer can drive active hypermutation of a lambda 1 transgene in Peyer's patch cells. The lambda 1 transgene under analysis carried two marked V lambda 2 genes immediately upstream that could serve as sequence donors in possible gene conversion events. There was no evidence of sequence transfer to the hypermutated lambda 1 gene, suggesting that gene conversion is not a major mechanism for somatic hypermutation in mice.

Animals↗

PubMed1998

Intralesionally implanted cisplatin plus systemic carmustine for the treatment of brain tumor in rats.

BACKGROUND AND OBJECTIVES: The benefit of conventional chemotherapy for the treatment of malignant brain tumors, although limited, is real. A major obstacle in the treatment of these lesions is the ability to deliver drug across the blood-brain barrier (BBB). Local drug implantation, circumventing the BBB, has been a useful strategy for treatment of intracranial lesions, and may work synergistically with systemic chemotherapy. To test this hypothesis, either intraperitoneal (i.p.) carmustine or cisplatin was combined with the intracranial (i.c.) administration of polymer-delivered cisplatin in rats with intracranial tumors. METHODS AND RESULTS: 9L gliosarcoma tumor cells (5 x 10(3)) were administered through a right frontal lobe cannula in rats 7 days prior to treatments. Cisplatin-loaded biodegradable polymer was then administered via the cannula, with free cisplatin or carmustine injected i.p. Animals were monitored for 60 days post-treatment. In experiment 1, i.c. cisplatin at a dose of 0.5, 1.0, 2.0, and 4.0 mg/m2 resulted in a mean survival time of 34 +/- 3, 39 +/- 14, 47 +/- 11, and 31 +/- 20 days (MST +/- SD), respectively, compared to 26 +/- 4 days in the control group and 30 +/- 7 days in the group treated with 50 mg/m2 i.p. free cisplatin. In experiment 2, i.p. free cisplatin at 25, 40, 50, and 100 mg/m2 resulted in a MST of 28 +/- 3, 30 +/- 4, 32 +/- 3, and 14 +/- 8 days, respectively, compared to 26 +/- 1 days in the control group. In experiment 3, the MST in the groups treated with 0.5 mg/m2 of i.c. cisplatin, 25 mg/m2 of i.p. cisplatin, 10 mg/kg of i.p. carmustine, i.c. cisplatin (0.5 mg/m2) plus i.p. cisplatin (25 mg/m2), and i.c. cisplatin (0.5 mg/m2) plus i.p. carmustine (10 mg/kg) was 30 +/- 4 days (P > 0.05), 28 +/- 2 (P > 0.05), 36 +/- 4 (P < 0.01), 32 +/- 3 (P < 0.01), and 50 +/- 11 days (P < 0.01), respectively, compared to the tumor control group (26 +/- 1 days). Long-term survivors (29%) were seen only in the i.c. cisplatin plus i.p. carmustine group. Additive toxicity was not observed. CONCLUSIONS: Intralesional polymer-delivered (i.c.) cisplatin plus systemic (i.p.) carmustine is highly effective for the treatment of intracranial 9L gliosarcoma in tumors.

Animals↗