Biomedical subjects

X D Zhou

Publications and source records attributed to X D Zhou.

At least 19 recordsLinked to original sources

PubMed2006

Effect of compounds of Galla chinensis on remineralisation of initial enamel carious lesions in vitro.

OBJECTIVE: To evaluate the effect of compounds of Galla chinensis on the remineralisation of initial enamel carious lesions in vitro. METHODS: Sixty bovine enamel blocks with early lesions were prepared and randomly divided into six treatment groups. The lesions were subjected to a pH-cycling regime for 12 days. Each daily cycle included 4x1min applications with one of six treatments; 1000ppm F aq. (as NaF, positive control); deionized water (negative control); or 4000ppm aqueous solutions of four G. chinensis extracts (GCEs); GCE, GCE-B, GCE-B1, or GCE-B2. Surface enamel microhardness was measured on the enamel blocks before and after demineralisation, and after pH-cycling, and percentage surface microhardness recovery (%SMHR) was calculated. The enamel specimens were then sectioned (thickness ca. 80microm) and examined by polarized light microscopy. RESULTS: All samples rehardened significantly compared to baseline. Fluoride had a significantly greater effect than all other treatments. In the GCEs groups, %SMHR was significantly greater than DDW for the GCE, GCE-B and GCE-B1 groups. There was no significant difference between the GCE-B2 group and DDW. Polarized light microscopy showed that the thickness of the surface layer increased obviously in all specimens including NaF group, GCE group, GCE-B group and GCE-B1 group. Negative birefringent band appeared in the lesions body and the depth of the lesions was obviously reduced. CONCLUSION: The present study has demonstrated the potential of three GCEs (GCE, GCE-B and GCE-B1) to effect net rehardening of artificial carious lesions under dynamic pH-cyclic conditions.

Analysis of Variance↗

PubMed2006

SPARC, an upstream regulator of connective tissue growth factor in response to transforming growth factor beta stimulation.

OBJECTIVE: To differentiate the effects of inhibition of specific small interfering RNA (siRNA) of SPARC (secreted protein, acidic and rich in cysteine) and siRNA of connective tissue growth factor (CTGF) in cultured human fibroblasts, and to identify potential interrelationships between SPARC and CTGF. METHODS: Fibroblasts from skin biopsy specimens of 2 normal individuals were transfected with siRNA of SPARC and siRNA of CTGF. The fibroblasts were stimulated with or without transforming growth factor beta1 (TGFbeta1) and examined by real-time quantitative reverse transcription-polymerase chain reaction to determine the transcription levels of several extracellular matrix genes. RESULTS: After exogenous TGFbeta1 stimulation, both SPARC siRNA and CTGF siRNA showed a protective role against overexpression of collagen genes. Following TGFbeta1 stimulation, SPARC siRNA-transfected fibroblasts showed a greater reduction in expression of the collagen genes compared with CTGF siRNA-transfected fibroblasts, as well as a significantly decreased expression of CTGF (P < 0.05). Using linear structure equations to quantitatively model a genetic network based on expression levels of each gene, a positive regulatory role of SPARC on CTGF, COL1A2, COL3A1, COL11A1, and TIMP3 was observed. However, the regulatory role of CTGF on SPARC appeared to be negative and very small, while the positive regulatory effects of CTGF on COL1A2, COL3A1, COL11A1, and TIMP3 were less than those of SPARC. CONCLUSION: The results of this quantitative comparison support the hypothesis that in these cultured fibroblasts, the regulatory effects of SPARC on some major extracellular matrix structural components are greater than those of CTGF. In addition, SPARC appears to regulate CTGF in a predominantly positive manner, while CTGF may act as a negative feedback control on SPARC following TGFbeta stimulation.

Cells, Cultured↗

PubMed2006

Shaping ability of progressive versus constant taper instruments in simulated root canals.

AIM: To compare the shaping ability of progressive versus constant taper shaft designed instruments in simulated root canals. METHODOLOGY: Simulated L- and S-shaped resin canals were prepared by ProTaper (progressive taper) and high elasticity in rotation 642 (Hero 642) (constant taper) instruments (n = 10 canals in each case). The pre- and post-instrumentation images were recorded and assessment of the canal shape was completed with image pro plus 5.0. The width of resin removed was measured at 9 measuring points. Incidence of canal aberrations, instrument fracture, preparation time and change of working length were recorded. In addition, the change of curvature and centring ability were also assessed. The data were analysed statistically using Student's t-test or Fisher's exact-test. RESULTS: In both canal types, Hero 642 instruments prepared canals more rapidly (P < 0.01) and maintained working length significantly more accurately than ProTaper instruments (P < 0.05). In canals prepared with Hero 642 instruments, there was less change in curvature. Instrumentation with ProTaper results in transportation towards the outer aspect of the L-shaped curved canals in the apical part and the inner aspect of the S-shaped canals at the curve. Hero 642 instruments had a better centring ability in the apical part of the canal, but resulted in shapes with a poor taper. CONCLUSIONS: ProTaper and Hero 642 instruments prepared curved canals rapidly, maintained working length well and were relatively safe without creating perforations and danger zones. In both canal types, Hero 642 instruments maintained the original canal curvature better, and had a better centring ability in curved canals because of its constant taper design. The taper prepared by Hero 642 instruments in the coronal part of the canal was generally poor.

Dental Alloys↗

PubMed2005

Frequency, species and molecular characterization of oral Candida in hosts of different age in China.

INTRODUCTION: Research indicates that host age is a determining factor in yeast carriage. From the neonatal period, humans go through several dentition periods, and the emergence and substitution of teeth and changes in living habits greatly change the environment of the oral cavity, and therefore influence colonization by oral commensal organisms, certainly including Candida spp. No previous study of Candida carriage by different age groups divided by dentition has been reported. This study supplies data on the geographical specificity of C. albicans genotypic subgroup distribution. METHODS: All test individuals came from a single geographical locale over a short period. Following mucosal swab sampling, CHROMagar Candida-yeast differential media were used to determine the frequency of carriage and species. All C. albicans strains were confirmed by PCR and PCR using primers reported to span a transposable intron region in the 25S rRNA gene was used to determine genotypic subgroups. RESULTS: The results demonstrate that for the tested population, the frequency of Candida species and the distribution of C. albicans genotypic subgroups varied with age group. With increasing age, the frequency of C. albicans decreases, non-C. albicans yeasts increases; Genotypic subgroup A is the dominating strain in the oral cavities of healthy young individuals. CONCLUSIONS: The influence of dentition substitution on oral yeast carriage was minor.

Adolescent↗

PubMed2001

Experience of 1000 patients who underwent hepatectomy for small hepatocellular carcinoma.

BACKGROUND: Recently, the implementation of screening programs using alpha-fetoprotein (AFP) and ultrasonography in high risk populations has identified increasing numbers of patients with small hepatocellular carcinoma (small HCC). The aim of this study was to summarize the authors' experience in patients who underwent hepatectomy for small HCC and the factors that influence or improve long term survival. METHODS: The study included 1000 patients who underwent hepatectomy for small HCC (< or = 5 cm) and compared them with 1366 patients who underwent hepatectomy for large HCC (> 5 cm) during the same period. A Cox proportional-hazards model was used for multivariate analysis of prognostic factors. RESULTS: Comparison between patients with small HCC (n = 1000 patients) and patients with large HCC (n = 1366 patients) revealed that those with small HCC had a higher resection rate (93.6% [1000 of 1068 patients] vs. 55.7% [1366 of 2451 patients]; P < 0.01), a higher curative resection rate (80.5% [805 of 1000 patients] vs. 60.7% [829 of 1366 patients]; P < 0.01), a lower operative mortality rate (1.5% [15 of 1000 patients] vs. 3.7% [50 of 1366 patients]; P < 0.01), better differentiation of tumor cells (Edmondson Grade 3-4; 14.9% vs. 20.1%; P < 0.01), a higher incidence of single nodule tumors (82.6% vs. 64.4%; P < 0.01), a higher proportion of well encapsulated tumors (73.3% vs. 46.3%; P < 0.01), a lower incidence of tumor emboli in the portal vein (4.9% vs. 20.8%; P < 0.01), and higher survival rates after undergoing resection (5 years: 62.7% vs. 37.1%; P < 0.01; 10 years: 46.3% vs. 29.2%; P < 0.01). No significant difference was found between survival after undergoing minor resection (n = 949 patients) or lobectomy (n = 51 patients) in patients with small HCC (P > 0.05). Reresection for subclinical recurrence or solitary pulmonary metastasis after small HCC resection was undertaken in 84 patients. CONCLUSIONS: Resection is still the modality of first choice for the treatment of patients with small HCC. Minor resection instead of lobectomy was the key to increasing resectability and decreasing operative mortality, and reresection for subclinical recurrence or solitary pulmonary metastasis was important approach to prolonging survival further.

Adolescent↗

PubMed2001

Chromosome 8p deletion is associated with metastasis of human hepatocellular carcinoma when high and low metastatic models are compared.

Recently, we found that chromosome 8p deletion might be associated with hepatocellular carcinoma (HCC) metastasis by analyzing the differences in chromosomal alterations between primary tumors and their matched metastatic lesions of HCC with comparative genomic hybridization (CGH) (Qin et al. 1999). To further confirm this interesting finding, the genomic changes of two models bearing human HCC with different metastatic potentials (LCI-D20 and LCI-D35), and the new human HCC cell line with high metastatic potential (MHCC97) were analyzed by CGH. Gains on 1q, 6q, 7p, and 8q, and losses on 13p, 14p, 19p, 21, and 22 were detected in both LCI-D20 and LCI-D35 models. However, high copy number amplification of a minimum region at 1q12-q22 and 12q, and deletions on 1p32-pter, 3p21-pter, 8p, 9p, 10q, 14q, and 15p were detected only in the LCI-D20 model. Gains on 1p21-p32, 2p13-p21, 6p12-pter, 9p, 15q, and 16q11-q21, and losses on 2p23-pter, 4q24-qter, 7q31-qter, 12q, 17p, and 18 were detected only in the LCI-D35 model. The chromosomal aberration patterns in the MHCC97 cell line were similar to its parent LCI-D20 model, except that gains on 19q and losses on 4, 5, 10q, and 13q were found only in the cell line. These results provide some indirect clues to the metastasis-related chromosomal aberrations of HCC and further support the finding that 8p deletion is associated with HCC metastasis. 1q12-22 and 12q might harbor a novel oncogene(s) that contributes to the development and progression of HCC. Amplification on 8q and deletions on 4q and 17p may be not necessary for HCC metastasis.

Animals↗

PubMed2001

A new siglec family member, siglec-10, is expressed in cells of the immune system and has signaling properties similar to CD33.

The siglecs (sialic acid-binding Ig-like lectins) are a distinct subset of the Ig superfamily with adhesion-molecule-like structure. We describe here a novel member of the siglec protein family that shares a similar structure including five Ig-like domains, a transmembrane domain, and a cytoplasmic tail containing two ITIM-signaling motifs. Siglec-10 was identified through database mining of an asthmatic eosinophil EST library. Using the Stanford G3 radiation hybrid panel we were able to localize the genomic sequence of siglec-10 within the cluster of genes on chromosome 19q13.3-4 that encode other siglec family members. We have demonstrated that siglec-10 is an immune system-restricted membrane-bound protein that is highly expressed in peripheral blood leukocytes as demonstrated by Northern, RT-PCR and flow cytometry. Binding assays determined that the extracellular domain of siglec-10 was capable of binding to peripheral blood leukocytes. The cytoplasmic tail of siglec-10 contains four tyrosines, two of which are embedded in ITIM-signaling motifs (Y597 and Y667) and are likely involved in intracellular signaling. The ability of tyrosine kinases to phosphorylate the cytoplasmic tyrosines was evaluated by kinase assay using wild-type siglec-10 cytoplasmic domain and Y-->F mutants. The majority of the phosphorylation could be attributed to Y597 andY667. Further experiments with cell extracts suggest that SHP-1 interacts with Y667 and SHP-2 interacts with Y667 in addition to another tyrosine. This is very similar to CD33, which also binds the phosphatases SHP-1 and SHP-2, therefore siglec-10, as CD33, may be characterized as an inhibitory receptor.

Amino Acid Motifs↗

PubMed2001

Multimodality treatment in hepatocellular carcinoma patients with tumor thrombi in portal vein.

AIM: To compare the therapeutic effect and significances of multimodality treatment for hepatocellular carcinoma (HCC) with tumor thrombi in portal vein (PVTT). METHODS: HCC patients (n=147) with tumor thrombi in the main portal vein or the first branch of portal vein were divided into four groups by the several therapeutic methods. There were conservative treatment group in 18 out of patients (group A); and hepatic artery ligation(HAL) and/or hepatic artery infusion (HAI) group in 18 patients (group B), in whom postoperative chemoembolization was done periodically; group of removal of HCC with PVTT in 79 (group C) and group of transcatheter hepatic arterial chemoembolization (TACE) or HAI and/or portal vein infusion (PVI) after operation in 32 (group D). RESULTS: The median survival period was 12 months in our series and the 1-,3-, and 5-year survival rates were 44.3%, 24.5% and 15.2%, respectively. The median survival times were 2, 5, 12 and 16 months in group A, B, C and D, respectively. The 1-, 3- and 5-year survival rates were 5.6%, 0% and 0% in group A; 22.2%, 5.6% and 0% in group B; 53.9%, 26.9% and 16.6% in group C; 79.3%, 38.9% and 26.8% in group D, respectively. Significant difference appeared in the survival rates among the groups (P < 0.05). CONCLUSION: Hepatic resection with removal of tumor thrombi and HCC should increase the curative effects and be encouraged for the prolongation of life span and quality of life for HCC patients with PVTT, whereas the best therapeutic method for HCC with PVTT is with regional hepatic chemotherapy or chemoembolization after hepatic resection with removal of tumor thrombi.

Adult↗

PubMed2001

Telomere erosion is independent of microsatellite instability but related to loss of heterozygosity in gastric cancer.

AIM: To correlate the length of the telomere to microsatellite instability (MSI) and loss of heterozygosity (LOH) of APC, MCC and DCC genes in gastric carcinomas. METHODS: Telomeric restriction fragment (TRF) length of gastric cancer was measured with Southern blot. LOH of APC, MCC and DCC genes, microsatellite instability (MSI) and frameshift mutation of hMSH6, TGF-betaRII and BAX genes were analyzed by PCR-based methods. RESULTS: Sixty-eight cases of sporadic gastric carcinoma were studied for MSI using five microsatellite markers. MSI in at least one locus was detected in 17 (25%) of 68 tumors analyzed. Frameshift mutations of hMSH6, TGF-betaRII and BAX were detected in 2,6 and 3 of gastric carcinomas respectively showing high MSI (> or = 2 loci, n = 8), but none was found in those showing low MSI (only one locus, n = 9) or MSS (tumor lacking MSI or stable, n = 51). Thirty-five cases, including all high MSI and low MSI, were studied for TRF. The mean TRF length was not correlated with clinicopathological parameters. No association was observed between TRF length and MSI or frameshift mutation. On the contrary, LOH at the DCC locus was related to telomere shortening (P<0.01). This tendency was also observed in APC and MCC genes, although there was no statistical significance. CONCLUSION: The development of gastric cancer can arise through two different genetic pathways. In high MSI gastric cancers, defective mismatch repair allows mutations to accumulate and generate the high MSI phenotype. In gastric cancers showing either low MSI or MSS, multiple deletions may represent the LOH pathway. Telomere erosion is independent of high MSI phenotype but related to the LOH pathway in gastric cancer.

Adult↗

PubMed2001

Abnormal beta-catenin gene expression with invasiveness of primary hepatocellular carcinoma in China.

AIM: To study the abnormal expression of beta-catenin gene and its relationship ith invasiveness of primary hepatocellular carcinoma among Chinese people. METHODS: Thirty-four hepatocellular carcinoma (HCC) specimens and adjacent para-cancerous tissues, 4 normal liver tissues were immunohistochemically stained to study subcellular distribution of beta-catenin. Semiquantitive analysis of expression of beta-catenin gene exon 3 mRNA was examined by RT-PCR and in situ hybridization. The relationship between expressions of both beta-catenin protein, mRNA and clinicopathological characteristics of HCC was also analyzed. RESULTS: Immuno-histochemistry showed that all normal liver tissues and para-cancerous tissues examined displayed membranous type staining for beta-catenin protein, occasionally with weak expression in the cytoplasm. While 21 cases (61.8%) of HCC examined showed accumulated type in cytoplasms or nuclei. The accumulated type Labling Index (LI) of cancer tissue and para-cancerous tissue was (59.9 +/- 26.3) and (18.3 +/- 9.7) respectively (P<0.01). Higher accumulated type LI was closely related with invasiveness of HCC. Results of RT-PCR showed the beta-catenin gene exon 3 mRNA Expression Index (EI) of 34 HCCs was higher than that of para-cancerous tissue and normal liver tissue. Using in situ hybridization, the signal corresponding to beta-catenin gene exon 3 mRNA was particularly strong in cytoplasm of HCC when compared with those of para-cancerous and normal liver tissues. Over expression of beta-catenin exon 3 was also found to be correlated with high metastatic potential of HCC. CONCLUSION: Abnormal expression of beta-catenin gene may contribute importantly to the invasiveness of HCC among Chinese people.

Cadherins↗

PubMed2001

Metastatic human hepatocellular carcinoma models in nude mice and cell line with metastatic potential.

Metastatic human HCC model is needed for the studies on mechanism and intervention of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient-like metastatic model of human HCC in nude mice (LCI-D20) and a low metastatic model of human HCC in nude mice (LCI-D35) have been established. All mice with transplanted LCI-D20 tumors exhibited extremely high metastatic ability including spontaneous metastasis to liver, lungs, lymph nodes and peritoneal seeding. Remarkable difference was also found in expression of some of the invasiveness related genes and growth factors between the LCI-D20 and LCI-D35 tumors. PAI-1 increased gradually following tumor progression in LCI-D20 model, and correlated with tumor size and AFP level. Phasic expression of tissue intercellular adhesion molecule-1 in this model was also observed. Using corneal micropocket model, it was demonstrated that the vascular response induced by LCI-D20 tumor was stronger than that induced by LCI-D35 tumor. Similar report on metastatic human HCC model in nude mice and human HCC cell line with metastatic potential was rarely found in the literature. This LCI-D20 model has been widely used for the studies on intervention of metastasis, including anti-angiogenesis,antisense approach, metalloproteinase inhibitor, differentiation inducer, etc. It is concluded that the establishment of metastatic human HCC model in nude mice and human HCC cell line with metastatic potential will provide important models for the in vitro and in vitro study of HCC invasiveness, angiogenesis as well as intervention of HCC recurrence.

Animals↗

PubMed2000

Inhibitory effects of synthetic beta peptide on invasion and metastasis of liver cancer.

PURPOSE: To study the inhibitory effects of synthetic beta peptide on invasion and metastasis of liver cancer. METHODS: Membrane-type intercellular adhesion molecule-1 (ICAM-1) expression of SMMC-7721 cultured hepatoma cells (7721 cells) was detected by immunofluorescence cell flowmeter. The adhesion of 7721 cells to fibronectin (FN) was assayed by the MTT method. The adhesion of 7721 cells to 7721 cells, 7721 cells to endothelial cells, and 7721 cells to lymphocyte cells was detected by adhesion assay. LCI-D20 human liver cancer metastasis model in nude mice was used in this experiment. One hundred micrograms of beta peptide per mouse were injected subcutaneously after tumor was resected premetastatically or postmetastatically to observe its effect on liver cancer metastasis after hepatectomy. RESULTS: Membrane-type ICAM-1 expression of SMMC-7721 cells treated by beta peptide was lower than that of the untreated cells. The adhesion of 7721 cells to FN, 7721 cells to 7721 cells, 7721 cells to endothelial cells, and 7721 cells to lymphocyte cells was also lower in the beta peptide group than in the untreated group. CONCLUSIONS: beta Peptide can block the adhesion of 7721 cells to FN, 7721 cells to some host cells in vitro, and inhibit HCC metastasis of LCI-D20 model posthepatectomy in vivo, so it could potentially act as an antimetastasis drug.

Animals↗

PubMed1999

The association of chromosome 8p deletion and tumor metastasis in human hepatocellular carcinoma.

To understand the genetic mechanisms underlying the progression of hepatocellular carcinoma (HCC) metastasis, differences of genomic alterations between 10 pairs of primary HCC tumors and their matched metastatic lesions were analyzed by comparative genomic hybridization. Several chromosomal alterations including loss of 8p, 4q, 17p, and 19p, gain of 5p and high-level amplification of 1q12-q22 were detected in two or more cases. The most significant finding is the loss of 8p which was detected in 8 metastatic tumors but only in 3 corresponding primary tumors (P = 0.03). This result suggests that the deletion of chromosome 8p might contribute to the development of HCC metastasis. Another interesting result is the detection of a minimum high-level amplification region at 1q12-q22 in HCC. This result provides a candidate amplification region in HCC for further study to identify amplified oncogenes related to the development or progression of HCC. Finally, this study provides a practicable model to detect specific genetic alterations related to the tumor metastasis through comparing the primary tumor and its corresponding metastatic lesion using comparative genomic hybridization technique.

Adult↗

PubMed1999

Invasion and metastasis of liver cancer: expression of intercellular adhesion molecule 1.

PURPOSE: To study the relationship between intercellular adhesion molecule 1 (ICAM-1) and liver cancer metastasis and to find predicting factors that could indicate the growth and metastasis of liver cancer. METHODS: ICAM-1 expression in fresh tissue of normal liver and hepatocellular cancer (HCC) was examined by immunoperoxidase staining. Serum soluble intercellular adhesion molecule 1 (sICAM-1) from patients with a benign HCC tumor, and the expression of ICAM-1 in the orthotopically transplanted LCI-D20 tumor of a nude mouse liver cancer metastasis model, and in human hepatoma, the tumor surrounding tissue and normal liver, was analyzed semiquantitatively by the immuno-dot blot method. Tissue ICAM-1 expression (mRNA level) was detected by Northern blotting. RESULTS: ICAM-1 expression in LD1-20 D metastatic liver cancer had a positive correlation with tumor size and the time after implantation. It increased suddenly as metastasis occurred being 3.03+/-0.51 before metastasis and 8.24+/-0.95 after metastasis, P < 0.01, then remained high, appending on the number of sites involved (monosite metastasis 5.48+/-0.49, multisite metastasis 10.05+/-1.17, P < 0.05). All six cases of normal liver samples were negative in anti-ICAM-1 immunohistochemical staining, 80.0% (36/45) of the HCC showed some ICAM-1 expression. The rate of positive cells was a little higher in large tumors, tumors with an intact capsule and tumors with metastasis, but there was no significant difference. It was noticed that two cancer emboli also had high ICAM-1 expression. The ICAM-1 concentration in HCC (13.43+/-0.09) was higher than that in tumor surrounding the liver (5.89+/-0.17, P < 0.01) and that in normal liver (4.27+/-0.21, P < 0.01). sICAM-1, like tissue ICAM-1, was higher in HCC patients than in patients (with benign liver tumor and normal controls. Both tissue ICAM-1 and sICAM-1 were higher in the metastasis group than in the group without metastasis (tissue ICAM-1 20.24+/-0.30 vs 10.23+/-0.12 P < 0.05; sICAM-1 12.18+/-0.25 vs 9.77+/-0.54 P < 0.05). Northern blot analysis revealed that ICAM-1 expression, as indicated by mRNA level, was also higher in HCC and in cancer emboli than in tumor surrounding liver and normal liver. CONCLUSIONS: Tissue ICAM-1 and serum sICAM-1 could indicate the stage of HCC, and the potential of hepatoma cells for invasion and metastasis. They may play an important role in the metastasis cascade.

Animals↗

PubMed1999

Is depression associated with immune activation?

BACKGROUND: Some research immunologists have suggested that major depression amd chronic fatigue syndrome (CFS) are characterized by immune activation. To test this hypothesis, we compared immunological function in patients with major depression and in patients with CFS who developed major depression after the onset of CFS to that of sedentary healthy controls. METHODS: Subjects completed the Centers for Epidemiological Study-Depression (CES-D) questionnaire and allowed venisection. We performed flow cytometric analysis on 13 groups of white blood cells and used a reverse transcriptase PCR method to assay m-RNA of eight cytokines. RESULTS: CES-D scores were high in both patient groups and did not differ significantly. We found no evidence for immune activation in either patient group. Instead the data suggested immunological downregulation in depression. LIMITATIONS: Not all the subjects in the two patient groups were off antidepressants. CONCLUSIONS: The data indicate that immune activation is not necessary in depression--either alone or with CFS.

Adult↗

PubMed1999

Immunological response in chronic fatigue syndrome following a graded exercise test to exhaustion.

This study was conducted to evaluate the immunological response to an exhaustive treadmill exercise test in 20 female chronic fatigue syndrome patients compared to 14 matched sedentary controls. Venipuncture was performed at baseline and 4 min, 1 hr, and 24 hr postexercise. White blood cells were labeled for monoclonal antibody combinations and were quantified by FACsan. Cytokines were assayed utilizing quantitative RT/PCR. No group difference was seen in VO2peak (28.6 +/- 1.6 vs 30.9 +/- 1.2 ml.kg-1.min-1; P > 0.05). However, 24 hr after exercise the patients' fatigue levels were significantly increased (P < 0.05). The counts of WBC, CD3+ CD8+ cells, CD3+ CD4+ cells, T cells, B cells, natural killer cells, and IFN-gamma changed across time (P's < 0.01). No group differences were seen for any of the immune variables at baseline or after exercise (P's > 0.05). The immune response of chronic fatigue syndrome patients to exhaustive exercise is not significantly different from that of healthy nonphysically active controls.

Adult↗

PubMed1999

Changes in immune parameters seen in Gulf War veterans but not in civilians with chronic fatigue syndrome.

The purpose of this study was to evaluate immune function through the assessment of lymphocyte subpopulations (total T cells, major histocompatibility complex [MHC] I- and II-restricted T cells, B cells, NK cells, MHC II-restricted T-cell-derived naive and memory cells, and several MHC I-restricted T-cell activation markers) and the measurement of cytokine gene expression (interleukin 2 [IL-2], IL-4, IL-6, IL-10, IL-12, gamma interferon [IFN-gamma], and tumor necrosis factor alpha [TNF-alpha]) from peripheral blood lymphocytes. Subjects included two groups of patients meeting published case definitions for chronic fatigue syndrome (CFS)-a group of veterans who developed their illness following their return home from participating in the Gulf War and a group of nonveterans who developed the illness sporadically. Case control comparison groups were comprised of healthy Gulf War veterans and nonveterans, respectively. We found no significant difference for any of the immune variables in the nonveteran population. In contrast, veterans with CFS had significantly more total T cells and MHC II+ T cells and a significantly higher percentage of these lymphocyte subpopulations, as well as a significantly lower percentage of NK cells, than the respective controls. In addition, veterans with CFS had significantly higher levels of IL-2, IL-10, IFN-gamma, and TNF-alpha than the controls. These data do not support the hypothesis of immune dysfunction in the genesis of CFS for sporadic cases of CFS but do suggest that service in the Persian Gulf is associated with an altered immune status in veterans who returned with severe fatiguing illness.

Adult↗

PubMed1999

Infrequent loss of heterozygosity of APC/MCC and DCC genes in gastric cancer showing DNA microsatellite instability.

AIM: To investigate the role of DNA microsatellite instability (MSI) in gastric carcinogenesis by studying associations between MSI status, clinicopathological features, and loss of genetic loci. METHODS: Six microsatellite loci and loss of heterozygosity at APC, DCC, and MCC were analysed by polymerase chain reaction based methods in 53 cases of advanced gastric cancer. RESULTS: MSI was observed in 32.1% of gastric carcinomas (17/53) and 20% of foci of intestinal metaplasia (3/15). Seven gastric carcinomas (13.7%) were MSI-high (MSI-H) (three loci or more) and 10 (18.9%) were MSI-low (MSI-L) (one or two loci). The frequency of MSI-H was higher in intestinal (25.0%) than in diffuse carcinomas (3.7%) (p < 0.05). None of the MSI-H tumours showed loss of heterozygosity at APC, MCC, or DCC loci. CONCLUSIONS: MSI may have an important and early role in a subset of gastric cancers, particularly the intestinal type. The MSI-H subset of gastric cancer has features in common with its colorectal counterpart, whereas MSI-L and microsatellite stable cancers appear to develop through the loss of heterozygosity pathway.

Adult↗