Search PubMed⌕ Search

Biomedical subjects

R Sun

Publications and source records attributed to R Sun.

At least 91 records · Page 5Linked to original sources
PubMed1999

Effect of diclofenac sodium and dexamethasone on cultured human Tenon's capsule fibroblasts.

BACKGROUND AND OBJECTIVE: To investigate the effect of diclofenac sodium and dexamethasone on cultured human Tenon's capsule fibroblasts. MATERIALS AND METHODS: Two experiments were conducted. In the first experiment, fibroblasts were treated with either diclofenac sodium or dexamethasone at different concentrations, and the cell growth was quantified by using Coulter counter and hexosaminidase methods at 1, 3, 5, and 7 days after adding the drugs. In the second experiment, the cells were treated with each drug for 24 hours and then the cultures were switched to a drug-free medium. The cell growth was quantified at day 7 after removing the drugs from the medium. RESULTS: In the first experiment, inhibition of fibroblast growth in a dose-dependent manner was observed from days 1 to 7 in the cultures treated with each drug. The inhibitory was more pronounced in the diclofenac treated cultures. The typical spindle-shaped fibroblasts treated with higher concentrations of the drugs became spherical cells. In the second experiment, inhibition was not observed when the cultures were switched to a drug-free medium. The spherical cells recovered to spindle-shaped cells and proliferated as normal cells. CONCLUSION: Our results have shown that diclofenac sodium and dexamethasone can significantly inhibit human Tenon's capsule fibroblast growth in a cell culture model. The inhibitory effect was not observed when the cultures were switched after 24 hours to a drug-free culture medium.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1999

[A rational selection of retroperitoneal lymphadenectomy for advanced epithelial ovarian cancer].

OBJECTIVE: To evaluate the rational application of retroperitoneal lymphadenectomy to advanced epithelial ovarian cancer. METHODS: 42 patients of advanced epithelial ovarian cancer were treated by retroperitoneal lymphadenectomy. Two groups were divided according to the residual disease post-operation. A: 26 patients with the residual disease < 2 cm; B: 16 patients > or = 2 cm. The regime of combined chemotherapy was the same in the two groups after operation. Clinical stage and pathologic grade showed no difference. RESULTS: The 5-year survival rate was 53.8% (14/26) in A and 12.5% (2/16) in B. There was a significant difference between the two groups (P < 0.001). CONCLUSIONS: The survival rate could be greatly improved for advanced epithelial ovarian cancer through retroperitoneal lymphadenectomy when the residual disease was smaller than 2 cm. This procedure would not be performed if the residual disease was larger than or equal to 2 cm.

Adolescent↗
PubMed1999

[Colorectal cancer: lymphatic metastasis and choice of operation].

OBJECTIVE: To study lymphatic metastasis of colorectal cancer for deceding the of dissection extent of dissection. METHODS: Six hundred and twenty-three lymph nodes from 74 cases of colorectal cancer were analyzed after D(3) resection. They were classified into peritumor, longitudinal spread, and upward spread groups. The metastasis rate of lymph node and its incidence were calculated. RESULTS: The metastasis rate of lymph node and its incidence in the peritumor, longitudinal spread, and upward spread (N(2) and N(3)) groups were 47.2% and 38.6%, 22.8% and 18.6%, and 29.7% (20.3% and 9.4%) and 10.2% (19.0% and 5.3%), respectively. The distribution rate of metastatic lymph node was 61.2%, 17.1%, and 21.6% in the peritumor, longitudinal spread, and upward spread groups, respectively. Within 2.0 cm on the anal side of rectal cancer, the metastasis rate was 3.7%, whereas in 2.0 - 4.0 cm no metastasis was observed cancer at the lower part of the rectum demonstrated a higher lateral metastasis rate. CONCLUSIONS: Colorectal cancer tends to metastasize to longitudinal and the risk of metastasis increased in the stage of pT(3) and pT(4) or low differentiation stage. Jump metastasis is also a feature. D(3) radical resection is necessary for colorectal cancer, but extended lateral lymph node needs enectomy or total mesorectal excision. No residual tumor tissue exists at the anastomosis site after low anterior resection when the excision distance is beyond 2.0 cm from the anal margin of rectal cancer.

Adult↗
PubMed1999

[Effect of gui xin tong on sorbitol and nerve conduction velocity in diabetic rats].

OBJECTIVE: To investigate the effect of Gui Xin Tong(GXT) on sorbitol and nerve conduction velocity in diabetic rats. METHOD: The model rats suffering from diabetes were induced by STZ, and blood sugar levels above 16 mmol/L were chosen for observation. The rats were divided into GXT group, AG group and control group. The nerve conduction velocity, aldose reductase activity and sorbitol in STZ induced diabetic rats were investigated. RESULT: Compared with the control group GXT could increase the sciatic nerve conduction velocity significantly (P < 0.05), decrease the RBC and sciatic nerve, aldose reductase activity, and RBC-sorbitol content. CONCLUSION: GXT has the effect of improving nerve conduction velocity significantly and reducing aldose reductase activity and sorbitol

Aldehyde Reductase↗
PubMed1999

[Omega-mercaptohexanoic acid self-assemble-modified gold electrode and its catalytic property for redox reaction of chlorophylls].

Omega-mercaptohexanoic acid (6-MHA) self-assemble-modified gold electrode has been made by the authors. The SERS spectrum and the variations of double-layer capacitance (Cd) which occurred in the formation of 6-MHA self-assembled monolayers (SAM) on gold electrode surface were studied. The structure model of this SAM was deduced. The results show that 6-MHA can form stable SAM on gold electrode, and this 6-MHA SAM electrode has obvious catalysis for the redox reaction of chlorophylls.

Caproates↗
PubMed1998

A viral gene that activates lytic cycle expression of Kaposi's sarcoma-associated herpesvirus.

Herpesviruses exist in two states, latency and a lytic productive cycle. Here we identify an immediate-early gene encoded by Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpesvirus eight (HHV8) that activates lytic cycle gene expression from the latent viral genome. The gene is a homologue of Rta, a transcriptional activator encoded by Epstein-Barr virus (EBV). KSHV/Rta activated KSHV early lytic genes, including virus-encoded interleukin 6 and polyadenylated nuclear RNA, and a late gene, small viral capsid antigen. In cells dually infected with Epstein-Barr virus and KSHV, each Rta activated only autologous lytic cycle genes. Expression of viral cytokines under control of the KSHV/Rta gene is likely to contribute to the pathogenesis of KSHV-associated diseases.

Amino Acid Sequence↗
PubMed1998

Serologic association of human herpesvirus eight with posttransplant Kaposi's sarcoma in Saudi Arabia.

BACKGROUND: This study investigates the association between human herpesvirus eight (HHV8) and Kaposi's sarcoma (KS), the most common cancer occurring in renal transplant recipients in Saudi Arabia. METHODS: A cross-sectional study of seroreactivity to HHV8 antigens in posttransplant KS patients from a tertiary care hospital in Riyadh, Saudi Arabia, and in control subjects without KS was conducted. Seroreactivity rates were determined using immunoblotting assays to detect antibodies to two lytic cycle HHV8 antigens: p40, an antigen found in infected cells, and sVCA, an HHV8-encoded small viral capsid antigen expressed in Escherichia coli. RESULTS: Antibodies to HHV8 p40 and sVCA were present in a significantly higher proportion of renal transplant patients with KS (13 of 14 patients) compared to renal transplant patients without KS (5 of 18; P<0.001) and compared to other control individuals (6 of 44; P<0.001). HHV8 seroreactivity was more common among patients with renal failure (28%) than among other control groups (7%). CONCLUSIONS: The serologic results provide evidence of a strong association between HHV8 and posttransplant KS in Saudi Arabia.

Antibodies, Viral↗
PubMed1998

Isolation and Fractional Characterization of Ball-Milled and Enzyme Lignins from Oil Palm Trunk.

Ball-milled and enzyme lignins were isolated from the trunks of oil palms and subsequently studied. The lignins were fractionated into pure milled lignin (PML), pure enzyme lignin (PEL), lignin rich enzyme lignin (LREL), hemicellulose rich milled lignin (HRML), and solubilized lignin obtained during enzyme treatment (SLET) fractions by a two-step precipitation method. The chemical and structural composition of the five lignin preparations was determined by using UV, GPC, FT-IR, (13)C NMR spectroscopy and nitrobenzene oxidation. Pure milled lignin and pure enzyme lignin fractions were found to contain rather low amounts of neutral sugars, 2.2-3.1%. The lignin fractions contained a high proportion of noncondensed syringyl units with small amounts of noncondensed guaiacyl and p-hydroxyphenyl units. Trace amounts of p-coumaric and ferulic acids were also found to be associated with lignin in the oil palm trunk cell walls.

Journal Article↗
PubMed1998

Recombinant human growth hormone promotes hematopoietic reconstitution after syngeneic bone marrow transplantation in mice.

Recombinant human growth hormone (rhGH) was administered to mice after syngeneic bone marrow transplantation (BMT) to determine its effect on hematopoietic reconstitution. BALB/c mice were given 10 microg intraperitoneal injections of rhGH every other day for a total of 10 injections following syngeneic BMT. Mice that received rhGH exhibited significant increases in total hematopoietic progenitor cell content (colony-forming unit-culture) in both bone marrow and spleen. Erythroid cell progenitor content (burst-forming unit-erythroid) was also significantly increased after rhGH treatment. Analysis of peripheral blood indicated that administration of rhGH resulted in significant increases in the rate of white blood cell and platelet recovery. Granulocyte marker 8C5+ cells were also increased in the bone marrow and spleens of treated mice. Red blood cell, hematocrit, and hemoglobin levels were increased at all time points after rhGH treatment. No significant pathologic effects or weight gain were observed in mice receiving repeated injections of 10 microg rhGH. Thus, rhGH administration after syngeneic BMT promoted multilineage hematopoietic reconstitution and may be of clinical use for accelerating hematopoiesis after autologous BMT.

Animals↗
PubMed1998

The correlation of telomerase and IL-10 with leukemia transformation in a mouse model of chronic lymphocytic leukemia (CLL).

Telomerase activity is upregulated in activated and malignant lymphocytes. We studied the correlation of telomerase and IL-10 to leukemia transformation in the NZB mouse model of human chronic lymphocytic leukemia (CLL). Telomerase levels increased from early to late leukemic stages, likewise IL-10 gene expression levels increased with the leukemic progression. The inverse relationship of telomerase and IL-10 levels to the survival of NZB mice was also established. Our data suggested that telomerase and IL-10 were involved in transformation in the murine model of CLL and the detection of telomerase activities might be of value in the prediction of CLL progression.

Age Factors↗
PubMed1998

Beta cyclodextrins enhance adenoviral-mediated gene delivery to the intestine.

PURPOSE: In general, the intestinal epithelium is quite refractory to viral and non-viral methods of gene transfer. In this report, various cyclodextrin formulations were tested for their ability to enhance adenoviral transduction efficiency in two models of the intestinal epithelium: differentiated Caco-2 cells and rat jejunum. METHODS: Transduction efficiency of replication-deficient adenovirus type 5 vectors encoded with either the E. coli beta-galactosidase or the jellyfish green fluorescent protein gene was assessed by X-gal staining or visualization of fluorescence 48 hours after infection. In vivo experiments were performed using an intestinal loop ligation technique. RESULTS: Several formulations of neutral and positively charged beta cyclodextrins significantly enhanced adenoviral-mediated gene transfer in the selected models. The cyclodextrin formulations studied increased adenoviral transduction in the intestine by enhancing both viral binding and internalization. Viral binding was significantly increased on cell membranes treated with positively charged cyclodextrins, as seen with confocal microscopy and rhodamine-labeled virus. Permeability studies and TEER readings revealed that the most successful formulations gently disrupt cell membranes. This enhances internalization of viral particles and results in increased levels of gene expression. CONCLUSIONS: These formulations can be of value in gene transfer to cells and tissues in which adenoviral infection is limited due to a lack of fiber and alpha(v) integrin receptors. They are simple to prepare and do not affect the ability of the virus to transduce target cells.

Adenoviridae↗
PubMed1998

High prevalence of antibodies to human herpesvirus 8 in relatives of patients with classic Kaposi's sarcoma from Sardinia.

A survey for antibodies to a recombinant small viral capsid antigen (sVCA) of human herpesvirus type 8 (HHV-8) was conducted in Sardinia, one of the world's highest incidence areas for classic Kaposi's sarcoma (KS). Prevalence of antibodies to HHV-8 sVCA was greatest in patients with KS (95%), followed by family members (39%) and a Sardinian control population age- and sex-matched to the relatives (11%). Within families, prevalence of antibodies was about equal among spouses, children, and siblings of KS patients, a finding that raises the possibilities of intrafamilial person-to-person or vertical transmission. Antibodies were detected 2-3 times more frequently in males than in females. The data show that prevalence of antibodies to HHV-8 sVCA correlates with the distribution of classic KS in a high- incidence area. Clustering of seroprevalence within some families suggests the presence of familial risk factors for active HHV-8 infection.

Age Factors↗
PubMed1998

Expression of mucin-type glycoprotein K88 receptors strongly correlates with piglet susceptibility to K88(+) enterotoxigenic Escherichia coli, but adhesion of this bacterium to brush borders does not.

Three antigenic variants of the K88 fimbrial adhesin exist in nature, K88ab, K88ac, and K88ad. Enterotoxigenic Escherichia coli (ETEC) strains that produce these fimbriae cause life-threatening diarrhea in some but not all young pigs. The susceptibility of pigs to these organisms has been correlated with the adherence of bacteria to isolated enterocyte brush borders. Whether that correlation holds for multiple K88 variants and over a broad genetic base of pigs is unknown and was the impetus for this study. We also desired to examine the correlation of the expression of a porcine intestinal brush border mucin-type glycoprotein (IMTGP) which binds K88ab and K88ac with the susceptibility of piglets to K88(+) ETEC. Of 31 neonatal gnotobiotic pigs inoculated with K88ab+ or K88ac+ ETEC, 13 developed severe diarrhea, became dehydrated, and died or became moribund. Another pig became severely lethargic but not dehydrated. In vitro brush border adherence analysis was not possible for 10 of the severely ill pigs due to colonization by challenge strains. However, of the 17 pigs that did not become severely ill, 8 (47%) had brush borders that supported the adherence of K88ab+ and K88ac+ bacteria in vitro, suggesting a poor correlation between in vitro brush border adherence and piglet susceptibility to K88(+) ETEC. By contrast, the expression of IMTGP was highly correlated with susceptibility to K88(+) ETEC. Of the 12 pigs that produced IMTGP, 11 developed severe diarrhea. The other pig that produced IMTGP became lethargic but not severely diarrheic. Only 2 of 18 pigs that did not produce IMTGP became severely diarrheic. Colonizing bacteria were observed in histologic sections of intestines from all pigs that expressed IMTGP except for the one that did not develop severe diarrhea. However, colonizing bacteria were observed in histologic sections from only one pig that did not produce IMTGP. The bacterial concentration in the jejuna and ilea of pigs expressing IMTGP was significantly greater (P < 0.005) than that in pigs not expressing IMTGP. These observations suggest the IMTGP is a biologically relevant receptor for K88ab+ and K88ac+ E. coli or a correlate for expression for such a receptor.

Animals↗
PubMed1998

Ultrasensitive reverse transcription-PCR assay for quantitation of human immunodeficiency virus type 1 RNA in plasma.

With the recent introduction of combination therapy, human immunodeficiency virus type 1 (HIV-1) RNA levels in plasma have been dramatically reduced, frequently to below the limit of quantitation (400 copies/ml of plasma) of the AMPLICOR HIV-1 MONITOR Test (Roche Diagnostic Systems). To achieve enhanced sensitivity of the AMPLICOR HIV-1 MONITOR Test, a modified specimen preparation procedure that allows input of RNA from 10-fold more plasma per amplification reaction was developed. This "ultrasensitive" method allows the accurate quantitation of plasma HIV-1 RNA levels as low as 50 copies/ml. A precision study yielded average within-run and between-run coefficients of variation (CV) of 24.8 and 9.6%, respectively. A multicenter reproducibility study demonstrated that the laboratory-to-laboratory reproducibility of this assay is good, with an average CV of 32%. The linear range of this test is between 50 and 50,000 copies/ml of plasma. RNA concentrations measured by the ultrasensitive and standard HIV-1 MONITOR tests exhibited good agreement within the shared linear range of the two methods. The two measurements were within a factor of 2 for 91% of the specimens tested, with the concentration measured by the ultrasensitive method being only slightly lower (median, 22% lower). Preliminary studies suggest that this assay will prove to be useful for predicting the stability of viral suppression in patients whose RNA levels drop below 400 copies/ml in response to highly active antiretroviral therapy.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Evaluation of a commercial PCR kit for diagnosis of cytomegalovirus infection of the central nervous system.

We evaluated the AMPLICOR cytomegalovirus (CMV) PCR kit for the diagnosis of neurologic CMV infections on 43 positive and 112 negative archived cerebrospinal fluid specimens originally tested by an in-house PCR method. The AMPLICOR kit showed sensitivity and specificity of 95 and 100%, respectively, versus the home-grown assay, indicating its utility in this clinical setting.

Base Sequence↗
PubMed1998

Evaluation of the AMPLICOR cytomegalovirus test with specimens from human immunodeficiency virus-infected subjects.

The AMPLICOR cytomegalovirus (CMV) test, a new qualitative assay for the detection of CMV DNA in plasma, was compared to conventional methods and quantitative PCR (Q-PCR) assays by using leukocytes and plasma from 179 blood samples from subjects with AIDS. For the diagnosis of CMV disease, cell-based assays such as a Q-PCR with polymorphonuclear leukocytes (Q-PCR-PMNL) and a pp65 antigenemia assay had the highest sensitivities but suffered from a lack of specificity. The best agreement between the results of the Q-PCR-PMNL assay and those of the AMPLICOR test was found when a threshold diagnostic value of 690 copies per 10(5) cells was selected for the Q-PCR-PMNL assay. In that context, the AMPLICOR CMV test had a sensitivity of 96.4% and a specificity of 95.3% when results were compared to results of the cell-based PCR assay. This threshold was close to the one described as associated with the best sensitivity and specificity for the diagnosis of CMV disease in a recently published study (4). Blood samples that tested positive by the Q-PCR-PMNL assay but negative by the AMPLICOR CMV test were associated with viral loads (mean, 785 copies, median, 96 copies per 10(5) leukocytes) lower than the viral loads of blood samples that tested positive by both assays (mean, 21,452 copies; median, 9,784 copies per 10(5) leukocytes) (P = 0.003). The AMPLICOR CMV test gave positive results at least 48 days before the development of symptomatic CMV disease in a longitudinal analysis of a limited subset of patients (n = 6) from whom sequential specimens were available for testing. In conclusion, the AMPLICOR CMV test is a very convenient assay combining rapidity, simplicity, and the possibility of batch testing. A positive result by this test seems particularly important since this implies, in most instances, the presence or the imminence of CMV disease, although a negative test result does not rule out disease.

AIDS-Related Opportunistic Infections↗
PubMed1998

[The predominant expression of Th2 type cytokines in human tumor cells].

OBJECTIVE: To observe the expression of Th1 versus Th2 type cytokines in human tumor cells. METHODS: The gene expression of Th1/Th2 cytokines in human tumor cells was detected by RT-PCR and RNA dot hybridization using IL-2 and IFN gamma as Th1 type cytokine genes, IL-4, IL-10 and IL-13 as Th2 type cytokine genes. RESULTS: There were predominant expressions of Th2 type cytokines in 20 different human tumor cell lines including 11 solid tumor and 9 hematogenous tumor cells. CONCLUSION: Predominant expression of Th2 type cytokines by tumor cells may be related to the evasion of tumor cells from immune surveillance.

Breast Neoplasms↗